Students and teachers beeing added to non-exsisting teams every day.

ChristianBergstrom Thank you for your response. 

We have a lot of "teams" or "channels". I don't really know what they are called if Im honest so I will just call them channels. Each class have idividual channels for their classes. The issue for us now is that even when channels have been removed or "archived" because that class no longer exsists teachers and students still get notifications that they have been added and/or removed from these channels a few times each day. Some get up to 30 notifications in a row. This is a problem because the notifications make it hard for teachers and students to find critical information in our teams. 
I suspect this happens because there is a big "sync" each morning. This whole system is handled by our citys IT department. Every school in our city is under this system. We have called them multiple times and asked them to fix this issue but they simply say its a "bug" with Microsoft and they can't fix it wich sounds wierd to me..
Thats why I asked here. 

Hope this cleared things up a bit. I'm sorry if I can't explain well enough, but the truth is I don't really understand the problem well enough myself yet.
Have a great day.