Asp Core 3.1 Identity Example doesn't work

This example no longer works:

https://docs.microsoft.com/en-us/aspnet/core/security/authentication/identity?view=aspnetcore-3.1&tabs=visual-studio#migrating-to-aspnet-core-identity

It used to, but it doesn't anymore.  I think it is because of Chrome 80 and the SameSite cookie, but I cannot find a solution.  I can register users, but all login attempts return invalid.