Luke23_00 wrote:
It seems like the issue doesn't occur in safe boot.
What may be the problem here?
How can I find out?
Well, that almost certainly means it is being caused by something installed. I provided two examples earlier, mos and CleanMyMac. CleanMyMac returns more than 10,000 hits when you paste this into a browser:
site:discussions.apple.com cleanmymac
CleanMyMac is one of the most problematic programs according to users' reports in Apple Discussions. The program may be on the surface innocuous, but it tends to delete files ("cleaning") and when they are files needed by the MacOS, that often disrupts normal system operation. There is no reason to install such cleaning apps.
mos seems to change the way the system interacts with mouse movements, and that's another good candidate. It has crashed multiple times according to Etrecheck.
You also have Bitdefender, an anti-virus that can absolutely slow down your Mac and cause lags. It shows "high cpu use" in your Etrecheck report.
By the way, Malwarebytes should be ok but I would turn off the real-time protection option (for now).
You can look through your Etrecheck report for all third party installed items that change the user interface. (Normal user applications like MS-Word or Adobe Acrobat would not be suspects.) To test, one needs to UNINSTALL them one by one, completely. Usually a company-provided uninstaller is required, but even those sometimes don't do it completely and sweep up is required.
A more drastic approach is to make several verified, reliable backups. Then follow Apple's instructions for preparing a Mac for sale/transfer, which involves completely erasing the Mac. Then run Setup Assistant or Migration Assistant to bring over only files and user accounts, not settings and not software nor applications. Then verify proper functioning. Then install things one by one to make sure you don't reintroduce the problem.
I would avoid the more drastic approach unless absolutely necessary. It is time consuming and one never wants to completely erase one's Mac if it can be avoided. I would try to uninstall things first to see if the problem goes away.
Clearly something is not right, Etrecheck shows numerous apps are crashing. Megasync, Apphousekitchen, ProjectLlama.cleanup, mos, Bitdefender and others are all possible suspects in causing your issues. Be especially concerned about ones that Etrecheck shows are crashing or using "high cpu." Those will slow your Mac down.