Attempting to perform my very first backup ever (to restore to a QNAP NAS), I have run into the very same problem as the OP.

I set the app not to nap and created a 30 second video from the MacBook Pro camera that I set on a loop.

Not sure which one did the trick but I've just completed about 175 of 500 albums when before I couldn't get through more than about 10-15 before having to restart the process.

Thanks for the tips

G

1) 568.2mm, 7K's, 5K5HC, 4x420's, D2500, MS200, moded Oppo BDP, Epson5020 FP
2) 218, 5200SE, DSW
3) MC200 core & MS200s to HK PA4000 house distribution