since i think it was not so clear what i did an even i did not exactliy get what was working i'll try to make it clear.
i have 2 pcs

at main pc i have 2 teams i can choose from: "3dudus" or "2dudus1pala"
at the other pc i have a "1dudu" team.

i followed the multiple computer instruktion and told the "3dudus" to allso launch "1dudu" the same with "2dudus1pala"
i made a aktion target group where all the 5 are in and chose "Group (others in):New Action Target Group" as target for ftl assist.

now what does work?
i wasent shure about it in my last post but now i did some testing.
if i log in with "3dudus" "1dudu" starts automatikly like it should. if i press a ftl key at one of the "3dudus" monitors all is fine the 3 and the 1 will assist. but if i press a ftl key at my other pc (1dudu set) all others will say they have no target.
first of all i thought it was some kind of connection problem (some kind of one way information only) but i have another mapped key that will move "Group (others in):New Action Target Group" for example backstep and that one works. so it must be sth wrong with ftl.
If i log in with "2dudus1pala" it is exactly the same.

please help me it is the last day i can test isboxer with multiple pcs because i wont be at home the next 3 days, so i can only play with my laptop.