Lost Position Mid Routine

I have had my machine for a while and would consider myself competent. I use VCarve Pro to create my G-Code so I am reasonably confident this is correct. I have recently had failures while routing and on my latest piece, I have had three different issues on the same piece.

1) While carrying out a pocket toolpath halfway through the first cut the machine stopped. I was not looking at the machine or the screen as it happened but when I did all the axes were not homed. I assumed a power failure and tried to resume but this did not work and I had to restart.

2) During the 2nd attempt the Z axis did not fully retract on a move and so cut through part of the job. I was monitoring this time and managed to stop using the E-Stop.

3) On my next attempt I was monitoring and heard a crunching noise as if the machine had hit something. (It hadn't) the router was then out of position and once again cut in the wrong place. This time I also got the error 'over temperature shutdown reported by driver(s) 3'

I have checked back in the console log and I only received the temperature error once.

I have no idea where to start any assistance is appreciated.

I still have this issue, and it's very frustrating.

In reply to point 1 in Roberts's reply, it is not a power cut. I have installed a UPS, but I still get the issue of all the axes forgetting their positions mid-routine. Roberts's 2nd point I have taken all apart and checked and could not find anything, but this would not be relevant to the axes forgetting position anyway.

I have also replaced all the motor cables in case something was shorting. I have also established that the issue only occurs when the router is running and under load. I have run multiple long routines without a router bit, and the issue does not occur. Every time it fails, the router is cutting. I use a Mafell router, and it is not overloaded. I have, however, run the Mafell power cable in the cable chain, could this be relevant?

Any further suggestions are appreciated