IpadOS 13.4.1 problem

This morning I startede to ude My New iPad Pro 12.9 2020 delivered with ipadOS 13.4. With success I connected an external HDD via my hyperdrive hub and played video from the HDD On the iPad pro. It worked without external Power supply. After lunch I upgraded to ipadOS 13.4.1 and NOW I Can no longer see my HDD via my hyperdrive hub (I also tried to connect external power to the hub, with no result) and The same negative result when I Connect it to the Apple USB A to USB c connector. what to do?