Can Someone please help me? ;S

Hi people ;D. Well i have 3 problems actually:
-My mobbing skills like Genesis and Meteor shower only hit 1 monster.
-When i kill monsters (tried with a lot of them) they dont drop anything, but when other players kills in the same spot they do drop.
-When im killing in FM Monsters dont respawn.
(When i started playing i didnt have those problems, they started in the second RB )
Thanks for your time ;D, Hope you can help.