iPhone Volume Not Staying Where Adjusted

I'm having a recurring issue, where, I swipe from the top right for my control center and adjust my volume (either up or down) and it doesn't stay where I put it. I close my control center and open it back up immediately and the volume lever is somewhere else entirely.

Most frequently, it's me turning it from all the way up, to the all the way down because I'm entering some kind of quiet area and I don't want to be one of those people embarrassed by their phone blaring a loud video in a quiet room.

I'll pull up my control center, swipe the volume from full volume all the way down to no volume, and close the control center. Then when I immediately open the control center again, it's somewhere in the middle. Sometimes it takes me three or four tries to get the volume to actually STAY at muted.

And just clarify, this has nothing to do with the RINGER, this is just phone volume for like, videos and stuff.

Why is this happening? How do I fix it?