Phone Presence Sensor changed device ID?

Our phone presence sensors have been working perfectly for quite some time when, yesterday, I notice my wife’s was suddenly not reporting properly. After trying re-booting the phone, looking in the IDE for duplicate entries, and a few other tricks I’ve learned, I finally noticed that the Device ID number had changed. (My webCoRE piston showed the ID rather than the name of the device and ActionTiles showed a “?” for the tile.)
So, I went through the SmartThings App sharing the available devices again (with webCoRE and ActionTiles), editing my piston and my tilesets and now everything is working again.
Has anyone else noticed the Device ID changing for no apparent reason? I’m flummoxed.