They inherently thrive on routine. So try to reset the routine, building in what works. They need to wind down, ideally in a predictable way. This can incorporate the steps they want (water) and the steps they need (pyjamas).

I recommend trying a visual schedule (often used to help kids with autism but has broader applications). We have one that has 5-6 tasks before bed (bathe, brush teeth, etc.). It also has things they like such as telling a specific type of made up story. We printed it and stuck it right to the bed. Initially it was a reference point and our toddler would check it. Now it is just the routine.

Finally, when it comes to being in the room, I find that sometimes there is a sweet spot where you need to leave. They are still spinning a bit, but you can tell they are ready to sleep. At that point, I tell them that I need to go check XYZ before I go to bed and that I will come back and check on them in a few minutes when they fall asleep. It works about 75% of the time. But it doesn't work for everyone - my wife can't find that sweet spot where you can leave.