You are not the first guy with this problem, by the way, I have currently no idea of the reason for that problem (I prefer to be honest...). (certainly related to a specific hardware).
If you have time, go here: https://www.lotatc.com/projects/lotatc/news starting from 1.0.0-rc5 dowload LotAtc client (no need server, only client) and try to see if you can tell me which version is working or not... As the problem seems to appears on launch, no need to have a server working...
Yes I can add it. -> todo list
IFF is on the way using UniversRadio (test in progress).
For AWACS, I get contradiction information on this, at this moment, I have decided that it is not possible in >realistic mode. At this moment, this step can be enabled for all radars or none, I have to change some code to be able to decide to activate this option following each radar capability, it is necessary to have something more realistic.