I have the same problems. I have worked with support on it, and there are some things they can do to make it better, but it still randomly comes and goes several times a week. Probably because of interference from my neighbors Wi-Fi.
I’ve tried a number of different things. (My background is network engineering and I worked with zigbee devices well before I started automating at home.)
Short answer: the smart things presence fob works great for some people. It has a lot of problems for some other people. Most of that seems to depend on issues of local interference.
You can solve most of the problems of the teleporting Zigbee fob by adding an additional device as a verifier. But it’s not something I would rely on for garage doors in particular. Or arming alarm systems. But that’s just me.
Different people have different needs and preferences when it comes to peace of mind.
Here are a couple of discussions about how people are addressing presence issues. They might give you some ideas, or at least a sense of validation. Just to be aware that the device does work great for some people. “all Home Automation is local.”
I myself am in the process of switching over to IBeacon detection as a presence indicator. It can be hard on the phones batteries, but it’s much more consistent at my house. I’m solving the battery issue by using a plugged in tablet at home as the detector and taking the iBeacon with me just like the ST fob.
Anyway, I think the ultimate answer on the Zigbee presence fob is that it should be advertised with one of those little footnote: “individual results may vary.” It certainly can work for a lot of people. But if you’re one of the ones it doesn’t work for, you may want to try a different approach.
BTW, it’s the only ST zigbee device that doesn’t use amplification, so I haven’t seen any of the teleporting issues with my other zigbee devices. Just the presence fob.