Does it still happen if you go back to 12.6? It is probably a coincidence, as the way Opus copies files has not changed. Something else may be causing instability or slowing things down. Shell extensions are often the cause of such problems.
Opus does not normally crash at all, so if you say it's crashing more now, presumably there was some instability before? Getting to the bottom of that is what we should do either way.
If any crash dumps were created, you can send them to us and we can tell you if the crash is caused by Opus or by third-party components (such as shell extensions).