Do your buffs get immediately cleared once you enter that antimagic field from a beholder's main eye (as shown by a debuff icon)? Pre-update 3 that has always been the case for me, but recently, there's been two instances where I got the debuff icon, but my buffs stayed. One in a Threnal quest, one in Tempest Spine.
Not that I'm complaining though..it's just..weird.