Question printer powers off main monitor

I have a Canon/hp C1860fw printer.
When powered off, all works normally.
When powered on, doing nothing, my main monitor(LG C1) gets powered off.
Shortly after the lg powers back on.
This repeats about every 1-2 minutes; very annoying.
I can print normally.
If I power off the printer, all works normally.
The printer is connected via usb only.
Even when the usb cable is detached the printer keeps turning the main display off.
I have, I think, reinstalled the printer drivers.

For now, I just power off the printer until I need to print something.

Any clue as to what is going on?
 
The LG48"tv is plugged into an ASUS 3070.
Driver is current.
The Printer is plugged into the wall.
I might add that all worked well a few weeks ago.
The only software maintenance was a windows update
When the printer powers on, there may well be a power surge.
But, after that when the printer sits there, doing nothing. Specs say 50w in ready state.
I will see if connecting via an independent power source does anything.

Update... I think we have something here.
I connected the printer power using an extension cord to a different wall circuit.
So far, things are operating normally.
I will have to go into the rat's nest of cables behind the monitors, ups, pc, surge protector and make sense of it all. UGH!!!
On reflection, I think the TV
is plugged into the ups for power failure operation.
I recall that setup operated as it should during a power outage.