RTK Surveyor - base mode not working

Hello,

I have been using SF RTK surveyor pair as rover and base. Our base broke so we ordered an RTK express+ to replace it. The SF RTK surveyor will not switch into base mode. I have tried configuring via wifi (base/rover switch flip within 1 sec) and reseting the unit by jumping ground to esp32 external reset button. Any insight would be appreciated.

Thanks,

Cameron