This is NOT a duplicate of https://feedback.bistudio.com/T86313 !
Reference to research as far as coding knowledge allowed: https://forums.bohemia.net/forums/topic/221167-addmpeventhandler-not-working-on-dedicated-server/
General description:
Swivel Targets adressed via their parent "base" object "Target_Swivel_01_base_F" will not react to EventHandlers placed on hitPart or hit (tested hit this just in case...).
The beheaviour of swivel targets being uncontrollable in MP environment in T86313 could be fixed via following code provided by user https://forums.bohemia.net/profile/900806-pierremgi/
This code is placed in each swivel targets init field in the arma3 editor:
0 = this spawn { waitUntil { !isNil {_this getVariable "BIS_exitScript"} && { !(_this getVariable "BIS_exitScript")} }; if !(isServer) then { _this setVariable ["BIS_exitScript",true] } };
Also user Best2nd (UO) found that the animation source for swivel targets no longer is "terc" but "popup_Source".
Using this in combination with "BIS_leaningEnabled" and "BIS_poppingEnabled" we were at least able to control the swivels actions across all connected clients to the dedicated server the mission was tested on.
While now animation and up/down control work, the swivel will still not react to EH input like normal popup targets do when shot.
Weirdly enough the EH already preconfigured for the swivel targets still uses terc instead of popup_Source. This is beyond my knowledge.