Signups/changing nickname/changing profile picture extremely slow. What could be causing this?

Description

I’ve been running the latest rocketchat docker image on a single server for the past 3 months, but recently new signups have been extremely slow, along with changing nickname/changing profile picture.
One weird behavior I’ve noticed is that if you navigate back to the chat after changing name/profile picture before the spinner goes away, you have to wait and watch all of your sent messages replayed in the channels.

Any ideas for how to fix this?

Server Setup Information

  • Deployment Method: docker
  • Version of Rocket.Chat Server: 3.3.0
  • Operating System: Ubuntu 20.04 LTS
  • Number of Running Instances: 1
  • MongoDB Version: 4.0 (docker)
  • Proxy: nginx 1.14.0 (SSL reverse proxy)