So you definitely need to open a support ticket with QNAP.
To look at the unit and see the load, you need to open an SSH session from your computer to the NAS.
Then once in the SSH session you use the TOP command to look at your loading. Something could be driving your load average way high. Or it could be something else.
Now, there is remote monitoring software with the AMIZcloud app. You will need a QNAP account for that - sounds like you don’t have one. So get that created and open a support ticket.