Mysterious yellow circle on Macbook screen

This yellow circle appeared on the right-hand side of my screen. It looked exactly like this (image isn't mine, it's copied from another thread)

I found other people had the same question but there was no answer. Here's the thread: https://discussions.apple.com/thread/252143197

You can't click it, or move it and it's there regardless of what applications are running. I closed all open applications (or I thought I did) and it was still there.

I'm posting because I found the answer (but the old thread is locked). It was Loom (from https://www.loom.com/) it has a feature for highlighting mouse clicks but it must've glitched out. I wasn't even using Loom at all, in fact I've never used it since I installed it.

If you click the Loom icon in the Menu bar and quit Loom, the yellow circle should disappear.