I noticed a variant of this problem when I’m in the scenario editor and choose via the menu for ‘Test’ to run the scenario:
The scenario will start on normal speed regardless of what my game speed setting is.
Changing the game speed succesfully updates the actual game speed, provided that you actually change the configured setting. Example: If I configured ‘fast’ initially and the game starts at ‘normal’ and I want ‘fast’ speed, then I need to change the configured speed to something other than ‘fast’ first and then change it back to ‘fast’ again.