For several weeks, anytime I host a custom game I have encountered this issue.
Changing one setting (maps, lobby settings etc.) will lock me out of changing any others. essentially the UI shows none of the tiles are selected and therefore changing more than one thing about a game is impossible.
Temporary workaround we have figured is to pass lobby owner to someone else to change the next setting, however this is inefficient and cumbersome.
This has been affecting our teams PUGs and practices and it is disheartening that this has not been fixed despite at least 3 patches hitting the games since its appearance.