Kudos to Epox - and a Problem

My 8RDA+ failed with what presumably was the bulging capacitors issue. After
a bit of a runaround with Epox, suggesting I try things that I'd clearly
delineated in the initial contact, they agreed to take it back even though it
was presumably out of warranty.

Back came a "new" (refurbed?) unit in a couple weeks - that's certainly fine
customer support in my book. I would have been pleased to pay for the
service, or for new capacitors to install myself.

But I can't get the behavior I've grown used to over the years with respect to
powering the machine up and down. Perhaps the fact that I purchased a new
case and power supply (Thermalrock Eclipse and Seasonic, respectively) while
waiting for the repair could be relevant, but I doubt it.

The computer is plugged into a good UPS, and I start the machine by actuating
the UPS. The computer immediately powers up. When I've terminated the
computer, and it shuts down, I turn off the UPS. Sounds pretty routine.

Well, I can't get this behavior after some reasonable amount of diddling of
the BIOS settings. If I change settings to allow the machine to start when
the UPS is actuated, then I have a problem shutting down: after the machine
shuts off, it immediately springs back to life and restarts. If I change the
BIOS to prevent that, then it won't automatically start when the UPS is turned
on - I have to push the powerup button on the computer.

Am I overlooking something obvious?

Art