I set up Evolution for my work office365 account. It worked exactly for 2 days. Now, it constantly keeps asking for password again and again and nothing shows up. I’m trying out Thunderbird with Owl plugin (trial) and that works flawlessly. Any tips on getting it to work on Evolution?

I understand your point completely. I’m a long time Arch Linux user, so I’m not averse to manual interventions.

I was considering tumbleweed on my work laptop. This makes me nervous. Was it easy to fix?

Try Puppy Linux on it. It runs with meager resources - ~100MB RAM, 250MB storage (only if you want to install it to disk). Everything runs in RAM and is blazing fast. It is a God send for older computers