The docs I work for (ENT's) recommend Afrin nasal spray for flying to help avoid the ear pain and pressure. The Eustachian tubes in your ears are connected to the sinus. If yawning doesn't help, try the Afrin or even Flonase.

I used to fly for Continental Express back in the 90s. The FAAs rules say that the airplane must keep the internal pressure at or below 8500 ft above sea level. ( if I recall correctly) So just try pinching your nose and swallowing as the aircraft goes up or down. I've flown several aircraft of varying manufacturers and they all work the same. So not sure what's happening. good luck.

Maybe the aircraft have different descent speeds? Just a thought...

I grew up in Hillsboro, OR.

That is Strange? Wonder why?

I had a similar situation back in 2010. I moved from Omaha to NYC (2ND time) and I couldn't hear out of my right ear for over a month.
Pretty sure it was due to the drastic atmospheric pressure difference.