I was playing on my op 8 gunzerker and nearly all the gear dropped by enemies are op 6 and op 7, is this some kind of bug.
Gear can always drop 1-2 levels below. Happens right across the game on all modes, and is a deliberate choice for the benefit of co-op partners who may not all be the same level at the same time. (It can also drop 1 level above, provided you haven’t hit a hard scaling cap like OP8, or level 72 in regular UVHM.) Playing solo doesn’t change this behaviour, btw - it’s quite normal.
Oh now it makes more sense now. Thanks for the help VaultHunter101