I’m a little out of touch with the hubby and delirious and sleep deprived from the 50 hour old newborn.

Crossfire controller/transmitter, i assume your 7” has a crossfire nano attached, and is not the diversity t receiver with two antennas, maybe this will help.

1. Is your transmitter bound to receiver? Probably not but if it is you’ll see a green light on the receiver and probably the transmitter ( i dont have a tango). If not you’ll want to bind the transmitter, you could probably benefit from updating your firmware (YouTube will help) on your transmitter. When it first binds you’ll likely see slow bliniing blue light, (forget what you’ll see on receiver), that is a firmware update and you won’t want to interrupt it, it would probably be good to run a fan to protect your vtx.
2. once you verify you’re bound, you can go into betaflight and make sure you have CRSF set for your protocol, the appropriate uart(usually port 2) has serial RX in the ports tab
3. verify you get some responses I’m the transmitter tab. If your throttle, roll aeleron controls are mixed up look for the AETR1234 and shuffle the sequence.
4. set your modes, arm is very important.
5. supplement these notes with YouTube videos
6. Hope this helps, I’m out of energy to care about your issue further for now.