I was forced to change UPS relatively recently (a few years ago) because the cheap but not bargain-basement PSU on my computer didn't work with the non-sine-wave output of my UPS. Call them poorly-made if you like, but either I got unlucky or they're fairly common.
Power supplies tend not to advertise their compatibility with non-sinewave power, but UPSes will certainly make it clear if they produce sinewave output. So the safe option is to get the UPS which gives the PSU what it's expecting.
Power supplies tend not to advertise their compatibility with non-sinewave power, but UPSes will certainly make it clear if they produce sinewave output. So the safe option is to get the UPS which gives the PSU what it's expecting.