First weird thing happened with my PS5 today, specifically the DualSense. When I finished playing last night, my DualSense said it had 2/3 power bar in the UI, so I opted to not plug it in. Put my PS5 into Rest Mode for the evening and went to bed.
Fast forward to a few minutes ago and I press the PS button on my controller to wake the console for the first time since then. Nothing happens. I try multiple times thinking it just didn't register the button press. Zero action. Console and controller don't turn on.
I plug the controller in hoping it will work with a direct connection. No orange glow, no nothing upon connecting.p it. I'm using the supplied USB A->C cable plugged into a rear USB A port. So, if the controller is dead, it's not charging in Rest Mode right now either.
I'm starting to panic a bit, and realize I'll try one more thing. With the controller still plugged in to the rear port, I manually hit the power button...BOOM! Controller comes to life, and console UI says the battery is "low". No crap!
Two things this (maybe) tells me:
1) The DualSense somehow completely drained itself overnight. Like over 14 hours and crucially it was not plugged in.
2) The USB ports will get into a state in Rest Mode where they no longer supply power.
Hopefully my story helps others if they find themselves in a similar predicament and how to deal with it. Hope it's just a fluke.
Everything else has been smooth so far in my experience.