Sorry to hear you’re having trouble …
I haven’t used the T-Beam – I’ve used a Heltec, and another custom ESP32 + LoRa device – but one quick comment: I’ve also seen some quirky Bluetooth connectivity behavior, where my Meshtastic device was listed inside the Meshtastic Android app, but didn’t seem available to ‘activate’. I’m not sure what solved it – but I think I recall that I went to the Android Bluetooth menu on phone (sounds like you did too), which also listed the Meshtastic device, and connected that way. I also think that after I did that once, connecting from inside the Meshtastic Android app went more smoothly.
Another thing to note: after one successfully initiates a connection (via the general Android Bluetooth settings, or from inside the Meshtastic app), the PIN is displayed on the Meshtastic-device screen. So if for some reason your screens aren’t working, you’re unfortunately blocked from connecting.
The face that the devices show up as available for Bluetooth connection makes me think that the Mesthastic firmware is running properly … but then, it also seems unlikely to me that you received two defective screens. Is it possible for you to post pics of how you’ve installed the screen – in case someone with experience might notice something odd?
Hope it can be resolved soon – it’s a really fun project to experiment with!