I was having the same issue with loadouts in version 2.18. I found that if you replace the "x_client/x_playerspawn.sqf" of version 2.18 with the same file from version 2.17, it fixes the loadout issue. It does add the backpack issue of version 2.17 back into version 2.18. Lesser of two evils in my opinion (I never had a problem with the backpack from version 2.17). This worked for the Operation Arrowhead version.