Fender GT100 and GTX7 Footswitch Problems

After contacting Fender tech support and having no success I thought I might see if you good folks have any suggestions.
I upgraded my Mustang GT100 MGT4 footswitch (which worked flawlessly) to the GTX7 footswitch that Fender advertises as compatible with my amp. The only way I can get it to function properly is to plug the GTX7 into the amp AFTER the amp has been powered up. Do you think this means that the voltage drops to the footswitch amp circuit during amp powerup? It's not the end of the world but I would appreciate any advice. This issue has been posted to Youtube and Fender forums by other GT100 owners. Thanks