Connecting Motorola Android to Sony TV

I am attempting to use my Motorola phone running Android 10 as a remote control for a Sony Bravia TV. The TV has wireless capability - it has a Sony wireless dongle in its USB port. The signal was weak so I used an old router as an access point and the signal is now strong. I gave the wireless network from the AP a unique name so that I could be certain that the TV and the android were connected to the same wifi network. The android phone successfully pings the TV's IP address. Some of the remote control apps correctly automatically identify the model number for the TV however none of them will actually connect to the TV -'TV not found' is the typical message. Anyone got any ideas about what I am doing wrong? Thanks.