Upgrading from .Net Core 2.2 to 3.1, SSL and Docker .net core images

Was forced to upgrade yesterday. Went to publish a Docker Container and the 2.2 images were no longer available.
So I made it through the code changes; well at least I think I did, but can't run my web app because of the SSL error.

I get the SSL connection not trusted error on both Firefox and Chrome. No option to ignore and accept the risk. Says my certificate is totally unsafe.

Changed the project file to 3.1, upgraded NuGet packages.
I tried IIS Crypto and set back to preferred.
Did the Dotnet https clean and trust
Installed Win64 OpenSSL to look at my localhost.pfx but can't really figure out how to use the program.
I realize now that my startup.cs only loads Kestrel for running in a Docker container so my pfx files are not the issue.
Ruled out HTTP1 or HTTP2

Issue two, finding the right Docker image to use in the container.
I was using ...
FROM microsoft/dotnet:2.2-aspnetcore-runtime AS base
FROM microsoft/dotnet:2.2-sdk AS build
Tried just changing the version number to 3.1, didn't work.

Yesterday just from about 15mins of research, I changed to
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1 AS base
FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build

But the build bombs; Can't remember why, I'll build it again.
Fallback package Xamarin, That gives me something to go on ...

1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: The "ResolvePackageAssets" task failed unexpectedly. [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: NuGet.Packaging.Core.PackagingException: Unable to find fallback package folder 'C:\Microsoft\Xamarin\NuGet\'. [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at NuGet.Packaging.FallbackPackagePathResolver..ctor(String userPackageFolder, IEnumerable

1 fallbackPackageFolders) [/src/jkirkerx/jkirkerx.csproj]<br />
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(IEnumerable

1 packageFolders) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(LockFile lockFile) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheWriter..ctor(ResolvePackageAssets task) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader.CreateReaderFromDisk(ResolvePackageAssets task, Byte[] settingsHash) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader..ctor(ResolvePackageAssets task) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ReadItemGroups() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ExecuteCore() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.TaskBase.Execute() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask) [/src/jkirkerx/jkirkerx.csproj]
1>Build FAILED.
1>
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: The "ResolvePackageAssets" task failed unexpectedly. [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: NuGet.Packaging.Core.PackagingException: Unable to find fallback package folder 'C:\Microsoft\Xamarin\NuGet\'. [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at NuGet.Packaging.FallbackPackagePathResolver..ctor(String userPackageFolder, IEnumerable

1 fallbackPackageFolders) [/src/jkirkerx/jkirkerx.csproj]<br />
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018:    at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(IEnumerable

1 packageFolders) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(LockFile lockFile) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheWriter..ctor(ResolvePackageAssets task) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader.CreateReaderFromDisk(ResolvePackageAssets task, Byte[] settingsHash) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader..ctor(ResolvePackageAssets task) [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ReadItemGroups() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ExecuteCore() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.NET.Build.Tasks.TaskBase.Execute() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() [/src/jkirkerx/jkirkerx.csproj]
1>/usr/share/dotnet/sdk/3.1.302/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(234,5): error MSB4018: at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask) [/src/jkirkerx/jkirkerx.csproj]
1> 0 Warning(s)
1> 1 Error(s)
1>