Front window switches open rear windows, but won't close them.

Rolled down all 4 windows at the same time from the driver master control switches.

A few minutes later, the front driver master switches would no longer move either of the rear windows back up. The local switches at both rear windows work properly, moving the windows both up and down.

First checked the child lock. It was off and still locks the rear window controls when depressed.

Tried the reset procedure as explained in the owner's manual. (close windows, holding switch for 6 seconds - then open, hold for 2 seconds). Did this for each at each of the rear windows, then again with the front master switches. Have tried this multiple times in various orders. Tried holding the switches for 10 seconds or longer. The fault persists.

What could cause the two driver's master switches for both rear windows to fail at exactly the same time, and fail in a way that the front switches will open the rear windows, but not close them? Perhaps rolling down all windows at the same time overloaded something? 12V battery is an 18 months old Interstate, battery diagnostic menu indicates it's good at 12.4v. Vehicle is a 2015 Prius 2.

 

Could see that if only one of the rear window switches had been impacted. But both were, at the same time.

And the front switches still properly roll the rear windows down.

Are there separate wires for the up controls and down controls? Even if that's the case, it seems unlikely that both front switches use the same wires for both of the rear windows. Which would mean both switches, or both wire pairs failing at the same time, and in the exact same way. This seems unlikely.

Feels like a software problem, or maybe a bad relay, if the system uses relays.