Practically every game made with Godot and exported to HTML5 won't run in Firefox for me. I usually get
Index out of bounds
At first I thought it was a Godot issue but then I hit F12 and noticed on one occaison it was because I block third party cookies - and Godot V2 tried to talk to a random website unrelated to the game. I checked and Godot V3 doesn't do this.
So I think its my settings in Firefox but I can't work out which one. Unity games in HTML5 seem to have no issue but Godot ones do. Any ideas anyone?