Is it possible for the 9 month sleep regression to only hit naps?!

My 8.5 month old LO (who I would never call a champion napper) stopped napping yesterday. He took and AMAZING nap yesterday morning (almost 2 hours!) unheard of for my chronic 30-45 minute napper. Then hasn't napped since.

He is obviously sleepy this morning, but screams and screams the second I put him down. He wont even fall asleep while I hold him which was always my go to when nothing else worked. He just wanted to lie there with his eyes open.

He's been extra clingy since last week too. Could this be the start of separation anxiety? Or is this the 9 month sleep regression and it's only a matter of time until it hits night time sleep too?

ETA: I just googled and found out there's a wonder week at week 37 (he's just a few days over 37 weeks). OMG