Are they all running that same firmware? If so, try the latest from here.
My machine in the lab does not seem to do what all yours are, but mine are all running much more current firmwares so if it was indeed a glitch at some point, it is possible it has been resolved in the past already.
If they are on different firmwares, my guess would be that they were setup with a clone file that possibly was corrupted, or had a corrupt setting and it was spread across the devices.
Of course I'm guessing, and doing so with limited information.