“IMPORTANT! A problematic update to MyPhoneExplorer Client (the app on the cell phone) is currently causing increased problems. The problem has already been fixed and an update will be distributed by Google in the next few days. If you can’t wait that long then use the current beta version until then”
(MyPhoneExplorer | Forum)
The App was updated recently in the Play Store, I don’t know whether this is the problematic update or the fix. The MyPhoneExplorer Forum seems to be down for the moment with an internal server error.