VAC1 getting "suspended" on its own

[JJ4SDR]

Was enjoying an SSB contact just now and all of a sudden the radio didn't put out any RF at all. I powered down the hardware, started up Thetis software, put out a few calls and then again, out of the blue, the radio stopped putting out RF after just about 1 minute. I thought I would take a look at the Audio/VAC1 form and noticed that the graph, to the right of the "VAC1 Monitor" was no longer tracing or doing anything, it was "frozen." Radio works fine if I switch to CW. I have never observed this behavior previously.

The weirdest thing was that I was still able to receive (VAC1 used with my external speakers too). Wouldn't the receive sound also not be audible if VAC1 gets "suspended?" It was if the VAC1 box gets unchecked, resulting in no RF going out from the radio. Have the amplifier on most of the time and its RF power output meter showed ZERO W out.

UPDATE: I always have DUP on and I could see there was a signal, but just no RF going out from the radio. Very peculiar.

What could be causing the above?

Juha
NI2M

[JJ4SDR]

Was on 20 last night for about 1 hour (I rolled back to Protocol 2, v.2.1.18 version) and made 2 contacts. Rag-chew type contacts. Absolutely no problems at all .

I am not sure if I can draw any conclusions from this though as I had been using Protocol 2, v.2.2.2 for around 3 weeks and this "glitch" manifested itself only on one day. So, I will report back later, telling if all is well now .

73,
Juha
NI2M