I have updated the firmware per RPi.org instructions on both.
Which firmware and which instructions?
How old is that OS image? What you're seeing is the sort of behaviour I'd expect when the OS post dates the launch of the 3B but pre dates the launch of the 3B+ and hasn't been updated.
If you followed the instructions for upgrading the firmware on a a 4B, 400, 5, or 500 that will have done nothing. Neither the 3B nor the 3B+ has an updateable firmware. Ecerything but the first stage bootloader (which is built into a ROM inside the SoC) is on the SD card. Those are the files you need to update. But not all of them.
Statistics: Posted by thagrol — Tue Aug 19, 2025 11:36 pm