What I did:
1) Switch on vhf1 (left side radio panel), tuned 122.8 (Vatsim unicom)
2) Switch on vhf2 (right side radio panel), tuned 135.550 (which happened to be online)
So far things worked, I wasn't receiving on vhf2/com2 as the receive switch was in it's default off position for vhf2/com2.
3) Switch on vhf2/com2 receive, now receiving on vhf2/com2, tuned to 135.550
4) Turn off vhf2/com2 receive, but still receiving on it. Text message received after turning vhf2/com2 receive back to off.
Also the transmit vhf1/2 buttons shouldn't be coupled to the receive knobs like they are now.
From previous picture, click vhf2/com2 transmit and we get here, it should only touch the transmit button:
And in this state vhf1 is still being received even than the volume knob is turned off.