Tony, Have you tried running the G2 from PiHPSDR in the radio? If it works properly from PiHPSDR, then it may be possible that P2APP has become corrupted in some way. Or,you need to reset your database in Thetis. If you are using the G2 without the front panel, hook a keyboard, mouse and monitor up...

It's not entirely clear from your post, but: - Did the Pi crash during this power supply event? or - When you saw the voltage had dropped and you "completely shut down the station within a few seconds" did you follow the proper shutdown procedure so that the Pi was not just crashed off? B...

Somewhere I thought I'd noted that the specification for DC power supply for the G2 was for 13.8v plus or minus 5 (five!) %, not the more usual 15%. Well, while transmitting a couple of days ago there was a power fault at my QTH that briefly dropped the DC voltage indicated on the shack power supply...

1st impressions: much improved over my 7000DLE, faster, greatly improved NR (try NR2), audio is wonderful, spectrum resolution much improved. Not sure how you are achieving those results. The RF hardware, ADCs, DAC and audio CODEC are identical or effectively the same as the 7000, and the Thetis so...