"Part of Coalition in Zone" in multiplayer

Just a quick sanity check on this one.

Is there any known issue with using the "Part of Coalition in Zone" trigger in multiplayer / with "Client" aircraft?

Trying to trigger a warning when enemy planes enter a certain zone, but it seems to go off at odd times when there couldn't possibly be any enemy units around, whether they are player or AI controlled.

Is there a behavior that I'm not aware of? For example, if a Red aircraft is destroyed in a certain sector, does it still read as a Red "unit" being left there?

No scripts / mods being used on the server in question. I just have it set up with a "Switched Condition" and a flag + timer that limits it to going off once every few minutes maximum.

I've seen some funny behavior I couldn't quite pin down on a similar prohect. I got it to work using a series of triggers: one switched condition for part of coalition in zone which sets a flag true, a second for all of coalition out of zone which sets it false again.

Then, a third switched condition displaying your message when the flag is true. Keep in mind things like damaged helos that have performed emergency landings are still considered alive for the purposes of that check.