Bluetooth headphones not connecting with Big Sur...but just on iMac

Others have posted about this same issue, but I wanted to chime in: last week I installed Big Sur on my iMac and MacBook, and now my iMac, but not my MacBook, is incapable to holding a connection to my bluetooth Marshall Major III headphones. It connects but then drops a few seconds later. I've looked up and tried many of the most common fixes, but none have worked. It's strange that my iMac can't connect, but my MacBook can, even though they're running the same OS. What gives, Apple?