I've noticed something interesting. My account was created on my laptop. Logging in there is fine. From the phone, with the spell checker on, the phone brings up my username. If I click on it, it enters my username into the username box, BUT WITH AN EXTRA TRAILING SPACE. I'll get an infinite spin if I use it as is, but can log in if I remove the trailing space first.

I had this problem at first, I believe when my registration was waiting for approval. Later in the day I cleared browser cache, and it just seemed to work.

Infinite spinner is most likely caused by an incorrect password.

I checked my password on mobile and found that I have been trying to login on Desktop with a password that is "off-by-one" char. lol 🤦

What Distro, DE, WM, Kernel, and are there any errors in your browser console?