@bsturgess Here is one of the threads I was taking about where they were also having issues with the Ultimate GPS same as you.
From this thread Adafruit GPS Photon problem
The GPS unit I recommend works right next to the Electron which leads me to believe it’s much better with interference immunity compared to the Ultimate GPS which may help solve your issues.
I’ve used the Electron and GTop GPS unit to log my position while driving hundreds of miles and it’s always worked perfectly while the Electron is ON and sending data.