Was the last Zone you left on the PC the default "Player" Zone? That may make a difference.
I have to tick the "Use Windows Discovery" checkbox for DMRA to find my TV. Though it isn't working at the moment... Neither is the MC installation on my Workstation...
Try the free version of BubbleUPnP on your phone (or
mConnect Player Lite if you are on iOS) and see if it sees the TV. BubbleUPnP and mConnect Player Lite (on Android) seem to find everything pretty well... Actually, neither BubbleUPnP or mConnect Player Lite are seeing my TV at the moment, and I have no idea why. It is turned on, on the network... DLNA is a frustrating technology...
A reboot of the TV had it re-appeared in the Apps, so that may be necessary for any testing. Mine is an Android TV, which may have been the issue here. DMRA sees the TV now as well, as does the MC installation on my Workstation, where there is only one Zone, the default Player Zone. But not my HTPC, which has multiple Zones.