I'm not sure what you have happening there.
But it can't hurt to update the firmware and try again.
If it still messes up, grab a screenshot of the error and post it (Take a pic with your phone or launch the remote control panel)
Remote control panel is here:
And also grab a fault for that time via Device > Notifications > Fault History (Just the one that happens at the time of the USB issue, not all of them)
USB connection mode is set to software tools
Probably have the port set to Direct Print Via Driver which allows you to print from a PC to the printer via USB, but disables print from USB storage.
Have USB ports enabled under USB Port Security. Print from USB is Enabled under Print From. When the USB flash drive is inserted, a message is displayed indicating there a no apps configured to support USB drive functionality.
What am I missing?