Samsung T3 and T5 won't connect to MBP Big Sur 11.5.2
I have a two Samsung portable SSDs, one T3 500GB and one T5 1TB, that I use with my MBP mid-2015 running Big Sur 11.5.2. Both drives require passwords to gain access to contents. Out of the blue, neither drive is accessible via the Samsung Portable SSD app. While the drives and their unencrypted content appear in Finder, the app reports "no Samsung Portable SSD is connected." Other posts suggest responding to the app's access request in Privacy and Security settings, but there is no such message in settings. What could cause both drives to lose access at the same time, and how can I restore it? Thanks very much for your help.
MacBook Pro 15″, macOS 11.5