i downloaded the dev dlc a while ago, played it then took a break for two weeks.. i come back and can no longer select to play those maps online.. but in public games sometimes we get them. is this normal? or wtf happened why cant i play strictly on my dlc

When you say 'select' are you talking about private matches or just the Map Pack playlist? If you're referring to the specific playlist, then yes, that's normal. Usually there's a period of time where you can play a mosh pit of multiple game modes on just the new maps, but that's always just temporary..eventually (usually a month) they get integrated into the regular rotation.