Opus freezes on me (and sometimes crashes completely) when viewing directories like Downloads or my Google Drive. Sometimes it would happen when I right-click something. Sometimes when I copy something from one folder to another.
Sometimes, it doesn't even freeze, but it will be extremely slow in loading the icon for the various files/programs (like, it will load one at a time). It's not a specific folder (i have double checked). It's random.
It could, yes. Defender is one of the worse antivirus in terms of how it affects other programs that are just reading folders or getting icons from files.
Following the guides Lxp linked is also advised. See if any crash logs were created, too.