Redownloaded Insider and have been trying to play Halo Reach, but not able to due to “max party size exceeded”. My party size is 1 one and the max party size says 0 if that helps.
This isn’t a glitch. You can find the aylist schedule for each day on the Halo Support site, noted in your email. Right now is Invasion. All others are disabled until it rotates to the next featured Playlist