I have investigated a lot of such cases while trying to help suspended LGs over the years.
Sometimes there is no good reason that I could find, but in the majority of cases it was quite obvious what guidelines were violated. Some issues can be fixed (undone) while others not.
I shared most if my experience in this tutorial:
https://www.localguidesconnect.com/t/how-to-get-in-and-out-of-trouble-the-main-post/351678
Most often suspensions are handled by an automatic AI system.