Wooha, some progress here during my absence.
I can exclude that AV is responsible. Even the fact that the problem appeared AFTER implementing the creators update and nothing changed else it is very unlikely that AV is responsible. No matter how, I
- deactivated AV -> Problem still exist
- Made exceptions for Folders to save and codeblocks.exe -> Problem still exist
- Deinstalled AV -> Problem still exists
Again: There MUST be any change within the creators update which cause this symptom. Interesting fact: Installing a new machine with the latest ISO (includes the creator update) does not lead to this issue. So only updated machines will be affected.
I will monitor this thread now on a daily basis. Let me know if you need more traces / logs.