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 about 18 months old, Interstate. Vehicle is a 2015 Prius 2.