I have a mission I just made for my group, that has some M4 Scorcher artillery as support. There is a "Support Requester" module that is linked to the player team leader and also linked to a "Support Provider : Artillery". The Support Provider : Artillery is also linked to the M4 Scorcher group. In offline and in local hosted multiplayer the artillery is able to be interacted with and called for perfectly. However, on my groups dedicated server the artillery support doesn't work correctly. 

When requested on the dedicated server, you are able to target on the map and the target map markers show up along with the ETA marker with the countdown, you select the munition type and the number, all of which appears to work correctly. The AI messages appear correctly as well, "Round complete" and "Splash!" when the rounds should arrive at the targeted area, however the rounds never arrive.

As a test we had some one in spectate watch the artillery while all this was going on, and the artillery never fired at all.

So once again, everything works offline in single player and also when playing multiplayer if hosted locally by someone. The modules seem to not work only in a dedicated server environment.