Probably same reason as other appliances, they can become faulty. Hopefully that's not the case with yours.
Try unplugging it for 30 seconds and reconnected it and performing a soft reset.
@Ray_YC I have had to do a soft reset but am unable to locate my activation code in order to set it up again. I am unable to access assistance online or over the phone due to COVI-19, any idea how I can get my activation code?
You'll need a replacement unit. When we organise replacement set-top-boxes, we also send out a pre-paid return kit. That's so you can return the faulty Fetch box back to our warehouse.
Right now, it's going to be diffuclt. Our general customer care team process these orders. Right now, they're prioritising critical enquiries. Unfortunately, you might have to hang on a little longer.
In the meantime please see Find Your Fetch Activation Code