Did I not get exp after firefight match?

Games Halo 5: Guardians
1

I finished two matches of mythic firefight using legendary boosts. After both games a red message popped up, and all I could read was something server, before it disappeared and I was booted to the main menu screen.

When looking at the post game stats, it shows the stats and exp gain from 2 games ago.

Did I not earn the exp and lose the boosts?

2

Sounds like you got disconnected mid-match. You won’t get any XP for those matches, but you won’t lose any boosts you used either. They will show up in your REQ collection after a couple of matches or after you restart H5.