GL2 fullscreen glitch

Hi all, I'm getting glitchy output when jit.world is in fullscreen using GL2. I'm attaching a video:

Interestingly, the glitch disappears when Max isn't being drawn at the front of the window stack, if that makes sense. Hitting Cmd+tab to bring up the application switching menu causes the glitch to stop, as does using Quicktime to make a screen recording (which is why I had to document this with my phone).

This problem is occurring on a Mac Pro 5,1 upgraded with a Radeon Vega 64. I tested the same patch on a MacBook Pro 2014 with an Nvidia GeForce GT 750M, and it doesn't show the behaviour, so I'm wondering if it's specific to the Radeon GPU.

The patch doesn't have this problem when using GL3, but unfortunately I need to stick with GL2 now because of GL3's current issues with Hap, as documented here: https://cycling74.com/forums/gl3-problems-with-hap-engine

Abridged support info for the machine with the issue:

"version" : "Version 8.0.8 (5586c03) (64-bit mac)",
"osversion" : "Mac OS X Version 10.13.6 (Build 17G65) x86_64",
"videoengine" : "hap",
"glengine" : "gl2",
"packages" :     {
    "gl3" : "0.1.1",
    "hap" : "1.0.5",
    "VIDDLL" : "1.2.1",
    "Video and Graphics" : "7.2.0",
}