How many files of what type(s)? That may point to a shell extension that's reacting to the rename, for example.
What type of folder are you renaming inside? (Local SSD, network drive, inside an archive, FTP, etc.)
How long did you wait?
If you make some process snapshots while the freeze is happening, we may be able to use those to see if it's Opus or another component causing the delay, and suggest what to do from there: Manually generating process snapshots