I had this issue when I forgot to remove the HA App from my old phone - had me confused for a few hours. Not sure you have the same issue though - but worth checking.
Also make sure the device is on the person so to speak :
I do have a tablet which I’m in the process of setting up as a dashboard and a phone which is a remote. Both devices are logged in of course.
Hhowever what I did is under the person entity i’ve only assigned my actual phone as the device to track. Unfortunately this didnt seem to do the trick.
If you have the option checked and are using the same login on the tablet as you use on your phone, it doesn’t matter what you manually assigned to the person entity. Device trackers that you removed will continue to affect the person entity as long as they use that login and you will likely see them added back to the list automatically on restart.