Thank you for your fast response. Just updated to 6.0.2-ci-3 and it is fixed

When updated, proget will fail to deliver NuGet packages. Log says:
Logged: 11/03/2021 09:35:52
Level: Error
Category: Feed
Message: Package file SomePackage/SomePackage.1.0.0.nupkg not found in CaseInsensitiveFileSystem.
Details: none

Version is 6.0.1. OS is Ubuntu 20.04

I could start the container and capture log for this:
Logged:
10/08/2020 05:59:36
Level:
Error
Category:
Web
Message:
An error occurred in the web application: Anti-CSRF validation failed because the expected token was not found.
Details:
URL: http://127.0.0.1:8087/0x44/ProGet.WebApplication/Inedo.ProGet.WebApplication.Pages.Administration.Licensing.AutoActivatePage/Activate
Referrer: http://127.0.0.1:8087/administration/licensing/activate
User: (unknown)
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0
Stack trace: at Inedo.Web.Security.AntiCsrfContext.Validate(HttpContext context)
at Inedo.Web.Handlers.JsonDataHttpHandler.AsyncHandler.ProcessRequestAsync(HttpContext context)
at Inedo.Web.AhWebMiddleware.InvokeAsync(HttpContext context)

We migrated to dotnet core platform and we got lowercase file errors and then problems with authorization (401) when downloading packages from VS. I tried a clean installation but it wouldn't activate auto or manually. In log I could read something about CORS, but unfortunately I didn't save those, I installed clean mono 5.3.12, activated it and uploaded packages and everything is working now.
I'm using docker linux containers.