Halo 3 EXP glitching

Well, I had recently leveled up to leatenit grade 1 overall and leatenit in social slayer. I had recently left a game and it down graded me by 1 ex. But it won’t let me get ex when I complete a match it doesn’t give me it. I had completed 2-3 games and still nothing.
Later in custom games some people were claiming they had hacks, they could be the problem but I don’t know.
Please help.

Quitting games removes 1 exp every time you quit. Have you quit multiple games? It could be that your service record hasn’t adjusted to catch up with the games you quit.

Well it de-ranked me. It says I need 1 exp to lvl but I won’t let me get that exp.

Sometimes it doesn’t let you get exp if you quit a lot, if you quit more than one match in a row, you’ll have to play a few before you start getting exp again.

Don’t know if that’s how it works or if it catches up, but in my case whenever I quit a match, I don’t get exp the next 1 or 2 games. Sometimes it will give me exp regardless, it’s old so who knows.