Hello el3triK_
we would need few data to analyze the issue.
Can you capture a procmon log and a dump of frozen process ?
1) download procmon tool from
https://docs.microsoft.com/en-us/sysinternals/downloads/procmon2) run procmon
3) induce the issue (start minecraft process and wait for a while)
4) save procmon log to file and upload it to avast (menu File->Save.. | check all events option ! and Native procmon format should be default)
Dump file can be created via task mgr (ctrl + shift + esc)
Select process and right click -> create dump file
Thank you !