Strange IFTTT behaviour

Because the ST phone presence has been unreliable for us, me and my wife also use IFTTT to activate a virtual presence from our phones, as a backup. We both have separate IFTTT accounts set up on our phones. And separate virtual presence switches in ST. Mine works perfectly, when I cross the geofense, IFTTT activates my virtual presence. However, when my wife’s phone crosses the geofence, it also activates my virtual presence, not hers. I have checked the IFTTT routine on her phone, it is set to activate her virtual presence. I have checked the IFTTT log. It says IFTTT activated her switch. I’ve also checked the ST log. ST says IFTTT activated my switch. Not sure if it is an ST problem, or IFTTT. So posting in both groups. Any ideas why it would be getting confused?