If you want to switch to 3.6 version of AGS (there is no need to do so, but if you're experiencing some issues with input, it will help) for you can do so by following the instructions:
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!

List of fixes:
-Fixed some texts regarding a poem.
-Fixed the darkness level on some objects so that they are more visible.
-Fixed clarity of click to advance dialogue option.