504 gateway error when logging in

Hi, hoping someone can help me with this.

I can’t log into my wordpress site. The strange thing is, the site itself works fine. And when I go to my wp-login screen, that loads fine as well. The problem only arises when I enter my credentials and hit ‘Log In’. Then it looks like it’s loading, but it takes a long time until the 504 gateway error pops up. I don’t feel like it’s an issue with a plugin (altho I could be wrong). Previous to my recent attempts to log in, I hadn’t logged in about a month. And back then I was able to log in without any issues. I am using Laravel Forge and Vultr to host my page if that helps any. I’ve emailed support and they aren’t able to help me. Does anyone have any idea on what could be causing the issue with my wp login screen?