Internet doesn't cut off. I have something checking that for me. And it's running straight off an SSD, I'm going to see what it's like with the wallets on a virtual for a few days. At least if the virtual dies it's not a big issue
The bit bugging me is that it only happens at night while I'm asleep. It will happily mine all day, system temps of my god and cup never hit the 50°C mark so I know it's not temps
When I've had this happen to me it is just the miner not allowing an interrupt to happen to trigger the monitor to open. Basically all I've had to do is unplug the network cable and wait for the miner to stale and lose connection to the pool/chain and stop mining. This allows the interrupt and i can just plug the cable back in and it will mine once connected.