I would guess you're not really cooking at 225. What are you using to take the temps?
Both grill temp and meat temp.
I use FireBoard for temp. Two probes in the meat and periodically an instant probe to be sure it’s accurate. For ambient I removed the WSM thermometer and installed a probe, plus one more on the grate. All connect into my FireBoard. At 160 I wrapped.
Ultimately I pulled it at 185ish to rest after basically giving up on getting to 195-200.
Cooking on a Webber Smokey Mountain. Feels smooth when piercing with a probe. I’m probably 20 butts in and constantly fighting this issue.Well, sounds like you're doing things right. What are you cooking on?
Did you probe it to see how it feels?