Xfinity remote power button gets out of sync with TV and sound bar

I have my Xfinity remote set to power both the TV and sound bar.  Most of the time it works fine, turning them both on or off together.  But sometime it gets out-of-sync, where the power button turns the TV on and the sound bar off, next press does just the opposite.  How can I get this button back in sync so both devices power on or off together?