I was so elated to find this thread that I had to create an account just to say Thanks 🙏.
I started using FCPX a few years ago and I frequently encountered that playback freezing bug. It's because of this thread I was able to identify that pest and temporarily (unfortunately not permanently) “kill” it.
I initially thought the reason for this freeze was because my MBP 13” (early ’15) was too old and needed more RAM and a better processor, so I convinced my better half to buy me a ’18 MBP 15” with 32GB of RAM (what can I say, my partner loves me). Once I got it, I was super stoked and ready get into FCPX and start editing. But disappointingly, I still encountered the same playback issue; not as frequent, but it still popped up it’s head 😠. This was obviously irritating considering this Laptop was brand new, but at that point, since google didn’t look into the future and find this thread 😂, I just accepted it. So whenever it froze up I did exactly what everyone else did: close/re-open FCP. But now, because of the info I found in this community, my faith in FCP has been restored (somewhat, I run into some random hold ups, but not often enough to warrant a google search).
Getting a new MBP wasn’t completely unwarranted; the MBP 13” couldn’t playback 4K from my GoPro Hero 7 since the video card couldn’t read HEVC.
I had the same issue with my apple brand AirPods. When editing with them, all of a sudden I'd get the spinning ball. Experts told me to try using proxy files but it didn't make sense - why all of a sudden? What was different? OH - started using bluetooth AirPods. Once I switched back to my wired headphones - back to normal.
Just reporting that I have this exact same issue on my new iMac whenever using my Air Pods Pro.. Put the Airpods in the case and listen via my regular speaker output and Final Cut is smooth as butter.. Try to use the Airpods and it's beach ball city..
Having recently had to dive into the art of Bluetooth connectivity, (unrelated to this thread), reminds me that there is a little-known collection of functions in the Bluetooth menu in the menu bar.
Hold down opt-shift and click on the Bluetooth menu and you will see a Debug option appear, with a submenu. These options in the submenu allow you to reset the Bluetooth module (in my experience devices usually reconnect), and Factory reset all connected devices, etc.
Neither of these options will do any harm, except that with the Factory reset you may have to reconnect the devices.
Another point worth mentioning, is that while Bluetooth uses a part of the 2.4GHz band that wifi doesn’t use, the close proximity of lots of powerful wifi will impinge on bluetooth connectivity, so it’s worth not having a wifi router 1m away!
While struggling with a low Bluetooth signal scenario, I found that resetting the Bluetooth module appears to make it search for a clearer channel on the frequencies it's allowed to use.
I wish I could reset the bluetooth in my Apple TV. Whenever I use my AirPods with it after a few mins the audio crackles out. It's unusable. But airpods have perfect connection to the iphone and computer.