USB not recognized after upgrade to Catalina OS/5.8.4

Hi all -

The USB 3.0 sticks I've been using for well over a year are suddenly not being recognized by RB. The iMac (2017) can see and use them as normal, but they are not showing up under "Devices."

So far, I've:

-restarted the computer

-uninstalled and reinstalled RB

-formatted USB and attempted contact with an empty stick (they're all in FAT32 as well)

-tried multiple USB sticks

-tried all the USB ports (only one of which worked, and then only once or twice)

What. Does anyone have any ideas for me? How is the latest RB upgrade working with the older OS? I'm considering attempting to downgrade from Catalina...