The "reverting at night to 3 concurrent sessions then back to 5 in the morning" scenario was one we considered and looked into but we didn't find any compelling evidence that something like that had happened. Not to say it hasn't been happening, just the information available to us didn't suggest it has been.
The team I'm working with to resolve this issue has asked for some additional details - specifically as precise a timestamp of an occurrence of this issue as you can feasibly provide (and as close to when it occurred as possible). And they request a list of your devices that are connecting, specifically the make / model of your phones, the OS version being run, etc. Feel free to PM me that info to keep it off the public board.