I was writing before that before I change the dietpi-userdata mountpoint to a new SSD disk everything work perfectly well with old HDD disk with the same USB 3.0 port from more than one year. I just wanted to change HDD to SSD because I bought it to speedup my server with DietPi.
but the SSD has a different adapter compare to HDD?
no
I tried a bit of an all-round method. I restored the system backup from the day before I swapped drives. I unplugged the new drive, plugged in the old one. The userdietpi directory was wrong, but I was able to mount (for the system) the new drive for the first time from the USB 3.0 port. It worked. I checked it for errors and it passed all tests. Then I restarted Rock64 and it worked fine with the new drive under USB 3.0 For the record, I should add that now the old drive only works from the USB 2.0 ports, while it does not work from the USB 3.0 port like the new drive did before.
Looks like your board is a bit fussy about replacing drives.