It's in Create Local>Coop which should be the multiplayer loadout, I never play on the singleplayer tab because there's no slider to change bot ratio there. I've done the repair option yet makes no difference, no MG's in either bunker. Actually there are only 4 total fixed MG's on the whole map. One MG42 Lafette at WN71. Then at WN73 there's one MG42 Lafette, one bipod MG42, and one MG34. Then there's the pickup kit at WN72.
It's in Create Local>Coop which should be the multiplayer loadout...