How do I better troubleshoot Home Assistant integrations and devices?

Ive been messing with HA for about 3 weeks now. Im getting used to how to add things, what to change, creating cards, UI, themes, starting to poke at node-red. However, I dont totally understand lower level troubleshooting and debugging. For example, when one of my devices gets “messed up”, how do I fix that vs. removing it and re-adding?
Current example. I updated HA last night and my ecobee stopped working. I can very well just remove it, and re-add it, going through the process again, but I dont want to do that because I want to learn.

That being said, how I would I begin to troubleshoot that connection? The logs dont seem to tell a whole lot. What is the underlying process for removing and re-adding and how can I do this manually?

HA is awesome, bu the learning curve is steep and the documentation is generally out-dated and incorrect. I want to better learn the lower levels of HA in order to be able to resolve issues more reliably and help others.

Thanks.

If you go into configuration on the side title column, scroll down too server control, choose check configuration, and that should give you a clue with what’s valid or not with your system files, with a situation such as yours, what i do is a hard reset of home assistant and that usually solves that issues.