Graphics Revert From Reforged to Old Warcraft 3 - But With Invisible Units/Structures Mid Game

This has been a bug for awhile, but it’s not one I can consistently reproduce. I’ll be playing a game (most often occurs in multiplayer…but does not seem specific to any map or game type), and randomly part way through the game, the graphics change from Reforged to Classic. But buildings and units are invisible. When I build new units, they’re visible, but with the Classic Graphics. But already created units and structures I have to do a lot of drag clicking to find. Sometimes the terrain turns black, sometimes it remains normal. It’s a very strange bug and very difficult to work around. But since it’s not consistent I’ve got no idea what triggers it.

I am playing on a 27 inch iMac. I don’t know if this is a mac only issue or if any PC users have encountered this as well?

Thanks Blizz team!