After the Catalina 10.15.7 update, my external TB3 hard drives are either disconnecting or aren't being recognized and a restart is required. I've switched out cables and tried different TB ports. It started immediately after the update. And of course, I'm still seeing the random shutdown issue that Apple has yet to resolve since August.
Over time I have seen that the problems seen after updates have always been problems which were already there, but which surfaced with the upgrade. I suggest that you download, install and run the free app EtreCheck. Be sure to enable full disk access. It will then generate a system report which you should save and then post below under "Additional text". That report provides a comprehensive view of the condition of your Mac. Then, I am sure that someone here will be able to offer some useful suggestions for resolving your problems.
Over time I have seen that the problems seen after updates have always been problems which were already there, but which surfaced with the upgrade. I suggest that you download, install and run the free app EtreCheck. Be sure to enable full disk access. It will then generate a system report which you should save and then post below under "Additional text". That report provides a comprehensive view of the condition of your Mac. Then, I am sure that someone here will be able to offer some useful suggestions for resolving your problems.
Catalina 10.15.7 update issues.
