I had the same issue, and after a few hours of investigation I found it was caused by MediaCore plugins crashing dynamiclinkmediaserver. I had the GoPro Reframe and Insta360Importer plugins installed in /Library/Application Support/Adobe/Common/Plug-ins/7.0/MediaCore.
Removing both plugins resolved the problem for me.
Log files I checked in the process:
~/Library/Logs/AdobeIPCBroker.log (indicated that dynamiclinkmediaserver was crashing)
~/Library/Application Support/Adobe/dynamiclinkmediaserve
...