4 yo waking multiple times a night for almost a year. Is it behavioral or something else?

My 4 yo has had inconsistent sleep since he started preschool almost a year ago. Before that, he slept through the night consistently from about 6 months–3.5 yo and needed no help to fall asleep or stay asleep.

He now wakes at least 1–2 times most nights. Sometimes I can tuck him back in and he goes right back to sleep, but other times he’s awake for 1–2 hours. He often comes into our room between 1–4am and majority of the time becomes very upset when I try to leave his room or if his dad goes in, saying he’s scared and needing me nearby.

We’ve tried consistent routines, an OK to wake clock, returning him to bed, gradually reducing my presence, having dad do bedtime and nothing seems to work.

We’ve made some progress of needing me lying beside him until he falls asleep to me being able to sit in the hallway while he falls asleep. We let him in our bed when he’s sick but we all get bad sleep the nights he’s in there and it’s not something I want to make a habit of.

A few other things: he sometimes snores and wakes up very sweaty. He had his adenoids removed, which significantly improved his snoring and drooling, but I recently noticed him occasionally lightly snoring again. His current schedule is bedtime between 7-8pm depending on how long he was up at night and he always falls asleep within 5 minutes. He wakes up between 6-7 and hasn’t napped since 3.5.

We’re going to bring this up with his pediatrician, but I’d love to hear from other parents on if this ended up being a development stage for you or if you pushed for a sleep study/testing?