If the trick I suggested doesn't work, then trying to powercycle with the on/off button might work. However I've found sometimes I have to turn off/on the entire house power button (the rocker switch near the slide door). It depends on how your GT is wired (mine is 2017) and varies from year to year. In worst case, you can do a "factory reset" from the Fusion screen; you will lose stored addresses, but not any updated maps.
Leigh & Bettie
2017 Interstate GT