I’ll get straight to the point, I’m still stuck on episode 2 of spartan ops. I don’t know if I’m not doing something right but I really would like to play episode 5 of spartan ops.
Matchmaking is set by 343 weekly. Its currently on a re-run phase of previous weeks content. You can not select matchmaking for any other missions. You would need to use the “play chapters” option and have a friend play with you on Chapter 5.
Episode 5 should be on Matchmaking in 3 weeks if you can wait that long.