Print stops - randomly
I've just had a couple of instances where the print just stops in the middle of printing. I DO have octoprint running and issue prints via octoprint, NOT the SD card. Octoprint running on a Pi 4, fan, etc. BOTH are connected through a "decent" surge protector - NOT a UPS.
Symptoms: print just stops, X/Y/Z axis still "engaged", but nothing is moving/printing. The hot end is still at temp, so it's not as if the print was cancelled. The web page for octoprint is frozen, and just shows things as if it were normal and still printing, but it isnt'. I can ssh into the pi, so the pi doesn't appear frozen. I'm not seeing errors in the octoprint log - it just stops with the last gcode command executed.
Suspicion: I'm really wondering if the USB communication has been interrupted between octoprint and the Ender3V2 (running a 4.2.7 board). And octoprint just stops issuing gcode commands to the printer.
And since we are "that time of the year", it could be very momentary brownouts or power interruptions. Just enough to screw everything up - but leave things still appearing to be "normally" powered on.
Any ideas? I'm considering a UPS, and wondering if a 400VA or thereabouts UPS is enough power.