I have a similar problem. The names of most of my boxes and DVR on the phone app says Self-Insta now. Does not match the name on the box, which says master bedroom., living room, etc. It used to match but after an update it does not match. You cannot pick which box you want to control when they all have same name.
Same issue here. But mine just shows numbers and the screen names.
Have you tried powercycling the offending boxes? You could try changing the name again on the boxes, then connecting the tablet to the app while on the home network. Might also have to reboot the router. Also delete history and cache on the app before you reconnect.