iPhone ringer volume automatically lowers itself

The ringer volume on my iPhone 16 Pro Max is constantly changing itself. I want it to stay full volume for my alarms, but every night when I change it, by the next night, it's significantly lower in volume and I have to change it again. I have "change with buttons" turned off. Attention Aware is disabled. I unpaired my apple watch and turned it off completely. I removed my phone from my car's bluetooth settings and disabled bluetooth on my car. My phone is fully up to date. I've restarted it many times. I don't have any automations set up. The only thing I can think of is that my Sony ear buds are somehow messing with it, but I can't figure out if that's true or even how. I also don't have any volume limits or accessibility settings set up. HALP