Literally 50% of the times when I zone, my main hand weapon will become invisible until I re-equip it. I use 2H melee weapons. It doesn't seem to matter what weapon I use. I use an outfit, and if that matters or not I'm not sure.
I've been googling this issue and it seems this issue started happening around August 2018, and it's STILL around.
In this thread @ZOS_GinaBruno
posted that they're aware of the issue and working on a solution. Well, that's nearly 2 YEARS ago now!
Please fix this because it's so darn annoying having to re-equip my weapon constantly.