That was my assumption as well. Though, it might be a good idea to join the discord channel. Thanks.Anyway, I'm waiting for a reply from the Adobe Support team. I'll provide an update later on.

Removing the repoinit scripts added recently fixed the issue in my case. Thanks @pat-lego 

@zameer_abbas do you have this issue an a vanilla AEM 6.5 instance? I have the  similar one after Service Pack 6  installation. I haven't found the root cause yet. Meanwhile, you should be able to use /libs/granite/core/content/login.html as a workaround at the moment I guess.