Weapon, vehicles, etc. Kill progression stopped after reaching mastery level 12

yea i had this too, i guess they don't like people thinking initially they can farm the skins in co op, so they made a limit for mastery, about a lil' over 1/4 of the way to 40, just to only have players get the attachments and weapons they need for public environments, but i said that ain't happening, cause the pvp is way to toxic, besides, i would not do very well in it to begin with