Loss of bottom end on UR24c

Hi guys,
Not sure what’s causing it, but I’ve recently built a new PC with Windows 11 & for some reason there now appears to be a lack of bottom end coming from the outputs of my UR24c. Unfortunately, I mix on headphones, so I can’t cross reference with studio monitors, but I have my setup calibrated perfectly & my mastered tracks translate exactly on every system, the way they should. I’ve listened to several different tracks from other artists & there is definitely a lot of bottom end missing from them. It’s like there’s a massive boost around 800hz - 1500hz. Everything is sounding really harsh & tinny. I have 3 sets of reference headphones & they’re all sounding the same. I’ve looked in Windows settings & the DSP Mix FX app, but all appears to be as it should. I can’t figure out what Windows or the UR24c is doing to the sound, but something definitely isn’t right here. I’m now unable to produce or mix.

Any suggestions??? Is there some new hidden EQ setting in Windows 11 that I’m unaware of???