I am posting this one first. I will post all three separately, to reduce potential for confusion (on my part as well as for the reader).
I have no knowledge of how to start with that. I figure it will be better to wait for further information about that before (probably) compounding the problem and increasing resulting confusion/mis communication etc.You could also try the #define DEBUG thing with the NOT working baro + GPS oXs yourself.
Supplementary information (may or may not be relevant):
Taranis X9D Plus on OpenTx version 2.2.3
Companion version: 2.2.3
Computer operating system: Linux Mint 19.3
Arduino IDE version: 1.8.12
Barometer reading at time of testing: 1009 kp.
Atmospheric temperature 18 deg. C
Google Earth coords for same location as test above: 30.24 S 152.56 E to the nearest minute.
Arduino nano clone board used. (ex Banggood).
Proper old fashioned lead solder used throught!
I sincerely hope I have provided sufficient information.
Please let me know if I have not.
I will do the BMP280 Vario only test tomorrow.