I'll tell you what...as I had said the Developer had responded to my issue within minutes on the Discussion's Board. Now I don't know when they came up with a possible solution but when I got up this morning they had me try this and it worked:
1) Right click The Excavation of Hobs Barrow,
2) Properties
3) Betas
4) typing in that text input box "testformactest" WITHOUT QUOTES, hitting check code
5) Hitting the blue button that will appear (i believe it will write "Opt into mactest")
6) The game will begin downloading files and once that's done, you'll have the same but hopefully the issue will be resolved!
If you've already opted the game will update, and hopefully that will work, if it does, I'll push the change to the main branch!
AGS 3.6.0.35 is 1) currently in development, which means it's not stable, 2) this is wildly untested.
About 90 mb is what this update is.
Cloak and Dagger Games did not mess around with this issue. They were ON IT ! ! !