I have a problem when copying files from my MacBook Pro running Big Sur 11.4 to an external drive via USB. Even though the files are quite small the copying process freezes up. The only solution that works is a reboot but strangely only for a couple of minutes then it freezes again. I had the same problem with Catalina before upgrading to Big Sur. I have tried different USB interfaces. I have disabled the drive in Spotlight. On other computers there is no problem using the same USB drive. Does anybody have a suggestion?