Sore Jaw?

Hello!
newbie here.. happy to say that on my 3rd night as a "hosehead" that I slept all night with my mask and didn't feel like throwing it across the room! Yay for me! AM experiencing some new things after many years of not sleeping well, such as a caffiene buzz and sore muscles from sleeping in one position for too long.
What seems weird though is that I wake up with a bit of a sore lower jaw. Never been a tooth grinder as far as I know, so I don't think thats it. Anyone have any ideas?

Happy to be a part of the community.

Potentially clenching your jaw... trying to make sure that you don't have mouth leaks.

Doesn't take a grinder to have jaw problems