Thanks for your reply.
When I tested it I plugged my HD straight to the USB port, no powered hubs or power supply to my box. It is an HD I use to store random data I need to store, nothing critical, then it already had some data on it. However I am not able to test it again as I am not in my usual location at the moment - given the holidays.

I have tested speed with an NVMe drive plugged via USB with the relative USB case. It seems that speeds are normal there.

Read:
read

Write:
write

I had the official App Store version and I was not aware of that feature but I’ll test the beta version when possible.

Thanks for your help!