There are details and the solution here: https://answers.unrealengine.com/questions/815780/typehash-invalid-with-a-custom-online-subsystem.html
This is my isolated reply/solution from that post:
Found the fix for the hash issue. Instead of adding a hash, given the "fix" implemented by Epic in 4.20.3, we now need to override the following function in FUniqueNetIdUWorks, inherited from FUniqueNetId:
virtual FName GetType() const override
{
return TEXT("UWorks");
}