I can confirm this.
I recently tried to check/uncheck boolean variables based on other booleans in the game mode via construction script and this has absolutely no effect.
After some research I found that this has already been reported and is JIRA UE-20786. Please follow that link to our Public Tracker to monitor the status and please feel free to vote on the issue while you are there.
This is still unresolved according to the tracker and it’s been years. Game Mode is a core class, and really needs to be rock solid. I’d much rather these bugs get fixed than get new shiny rendering features. I really love the engine and the work you guys do, so that’s the spirit I’m making this comment in.