Iphone 16e volume intervals not working correctly?

I am using an Iphone 16e and am having issues with the volume steps through a usbc dongle being uneven and either too quiet or too loud with no in-between. I had the issue on ios 18 and tried updating to ios 26.1 which did not solve my issue. to be specific, it seems the volume slider with nothing plugged in works perfectly. that is it changes volume by each percent and the volume changes very smoothly when using touch to control the volume. however, when i am using my headphones/IEM’s with a dongle, the volume only changes volume at very specific intervals with no gradient between them. 2 of which are at 9% and 24%. these 2 intervals of volume have NO in-between and 9% is often too quiet while 24% is too loud. the funny thing is the higher you go the closer the intervals get which would be nice if 24% wasnt already too loud most of the time. Why cant we control volume by 1% intervals ONLY when using headphones? how do i fix this as this seems to be a very major bug. the phone clearly can change at 1% intervals as seen when nothing is plugged in. but it refuses to when actually using audio equipment.