This has been happening to me for quite a lot of flights recently, and I was flying just now and got a level 2 violation, I have screenshots of me sending like 10 messages and no response? How can I fix this and appeal this violation? They told me to change frequency to the one they told me to which I did and still no response.
I had the same problem once recently, with Heathrow Tower. He on guarded me multiple times in the departure line even though I was on his frequency and contacted him each time he on guarded me. Didn’t get a violation though since the communications started to work normally again when I was third in the line. I think it’s definitely a bug where the messages are not going through. I too have the latest version updated