CyberPower OLS1000A has a horrible high-pitched buzzing noise under load

I’ve had this CyberPower OLS1000A for only about 2 months, and it has developed a very annoying high-pitched buzzing/electrical noise.

The noise gets noticeably louder as the UPS load increases. It sounds like a high-frequency metallic/electrical “biiiiii” and it is extremely annoying, especially in a quiet room.

It is not the fan. When the UPS is running without supplying power to the connected equipment, I can hear the fan normally and there is no high-pitched noise. As soon as the UPS starts supplying power to the outlets, the high-frequency noise appears.

Has anyone else experienced this with the OLS1000A? Is this normal coil/inverter noise for this model, or could it indicate a problem with the UPS?

The unit is only 2 months old, so I’m trying to determine whether I should return it or request a warranty replacement.