This "Arma3" behavior was noticed, since last January 2022.
We believe that something was broken after a game update.
After a couple of "SAVE and EXIT" and "RESUME" of a multiplayer mission, the waiting time for the mission to start becomes unbearable.
I've done a couple of obvious checks and one odd thing is that, most of the RESUME "waiting time", the total host CPU load is not greater than 13%. This was tested in "Windows 8.1 Pro" and "Windows 10" computer Hosts with the same results.
I'm aware that community MODs are not considered by Bohemia support but there's a detail that may help troubleshooting the problem: We were forced to stop using the "Task_Force_Radio" or "Task Force Arrowhead Radio (BETA)" or "ACRE2" MODs, because we've noticed that after the first multiplayer "SAVE and EXIT" and subsequent "RESUME", such radio MODs do not work as expected anymore.
We believe that the game "SAVE and EXIT" operation is ignoring MODs/scripts states and such MODs stop working after the next RESUME, yet, if instead of "RESUME" the host "RESTARTs" that same mission, the radio mods start working again.
Also, the saved file size becomes smaller and the RESUME time becomes shorter.
In attach I'm sending the Eden Editor file, the multiplayer mission file PBO, 2 saved mission files folders (from 10 and 11 SET 2022) and the list of mods used to play the mission in html. {F2782226}