Likewise, GSX is currently unusable. Regarding the Fenix, there is a perfectly good push back option in the EFP under Ground Services. I would recommend disconnection GSX in the EFB otherwise it will activate once you set the beacon light. Another reason is if you do not disconnect, GSX will continue to set the Tug even if you continue to reset it until you have started both engines.
I am sure there will be fix soon.
Keith