Intermittent facial numbness (upper lip/nose/cheek), positional (side sleeping), resolves in 20–25 min — MCAS reaction or something else?

I’ve been getting these odd episodes of facial numbness over the past few days and I’m trying to make sense of it.
It’s always in the same area: upper lip, gums, nostril, and cheek next to the nose (not the lower lip or chin). It feels like dental anesthesia, not tingling.

What I’ve noticed:
- Happens when I sleep on my side/usually affects the side I was lying on
- Starts during sleep or right after waking up
- Goes away within 20–25 min (I’ve only noticed it after taking Benadryl, so not sure if that’s coincidence)
- Face looks completely normal, no visible swelling
- Sometimes I wake up with nasal congestion/runny nose

I also recently started eating rice again after not having it in my diet for a while, not sure if that’s relevant or just a coincidence.
ER ruled out stroke, and neurology didn’t think it sounded like a nerve issue???
I have MCAS and hEDS, so I’m trying to figure out if this could be histamine-related or more positional/sleep/pressure related.
Has anyone experienced anything similar or have ideas on what direction this points toward?