Re: Switching Gamemodes doesn't change mode.
There's no fix from Respawn, but there is a player side fix. After switching gamemodes, wait a few seconds before readying up.
When you first switch modes the game still has you in those mode's ques. This is probably because someone might change the mode a few times for wherever reason, and constantly moving them may not be ideal.
Thus, the mode you're set up for is being rate limited, and it waits for your final mode decision. The problem comes with the match being made before the next interval to check what mode you're set up for.