I just received the update this afternoon. No issues with the dashcam USB. I tested the Sentry Mode by bumping on the window. The driver’s side camera on fender (new left repeater) captured me walking up to the car and bumping the window. No problem with the USB.
The new update adds Recent and Saved folders under the TeslaCam folder. It also adds the Left Repeater and Right Repeater camera files to the existing Front camera file.
Just curious, what are the specs of your USB drive?