@sean Are you maybe creating backups or some other DB maintenance at about 22:00-22:20 UTC? 🙂
I just witnessed active connections skyrocket from 180 to 250 (and too many connections) in two seconds, after that it plummeted to around 20 connections and stayed there. I assume it started at around 20-40 and pushed to 250 really fast. Seems to happen at approximately the same time every day.