4 month regression?

Help! 4 month old has been waking every 2-3 hours overnight for almost a month.

Prior to this, he woke up once per night. We were able to insert a pacifier and he would go back to sleep for the rest of the night. Self weaned night feeds around 12 weeks.

When the wake ups first started, we used the pacifier to put him back to sleep, but that wasn’t sustainable.

We have been trying to CIO for a little over a week, but I feel like we haven’t seen much progress. Still wakes after each sleep cycle. Early in the night he can put himself back to sleep fairly quickly. However after midnight, it’s often an hour of on and off crying after each sleep cycle before he falls back asleep. I was worried he was hungry at first, but if we insert the pacifier (which we are trying not to do until 3/4 AM) he will fall right back asleep. I also tried feeding at that time and he took only 1-2 oz, so I don’t think it’s hunger.

Current wake windows are approximately 2/2/2/2. 3.5 hours total nap time (1.5/1.5/.5). Wakes up at 6:30/7 and in bed by 6:30/7.

Falls asleep independently at night within 5-15 minutes with no crying. Sleeping in a sleep sack in pack n play in his own room.

Naps are great. Falls asleep independently but uses pacifier to fall asleep. Usually spits it out once he is asleep and continues to nap without it.

Drinks 4-5 bottles a day totaling 28-30 oz. Weighs around 14.5 pounds.

Should I drop the pacifier during the day? I’m hesitant to mess with naps until we figure out nighttime for fear of making him overtired. Is this a sleep regression that I just need to ride out?