UI takes a long time to update changes at times
There have been times when testing a user's file upload, file moving, etc. that couldn't be confirmed or denied because of the UI not showing it for several hours. The first time this happened I spent hours trying to fix code that ended up not being broken which was quite a pain and waste. The other times it was inconvenient and annoying since I now knew I just had to find something else to do before thinking that I needed to change code on my end.