in home screen my it shows me at lvl 14 but when i am in a game it shows me typically a lvl and a half higher. This has been going on sense the start of beta 1. Also, I will play a game of push or scirmish and i will only recieve around 280 XP for time played when previous games would give me upwards of 2800-3500. it seems the low XP is random
This happens to me, too. My level on the server player list is always one higher than in the main menu. I'm not 100% sure but I think it also happened during the beta.
I haven't seen any abnormal XP gains, playing only Checkpoint. Although, I once got only 15XP but I only joined the game near the end, got a kill, died and won the match.
This might be related or maybe it should be reported as a separate issue:
Earlier today I played a match that went well and quit the game after. The next time I launched the game and queued for a match I got put into a match where the players were defending the last objective. We won the round but I didn't even get to spawn. In the match results screen I got the exact same results as the last time I was playing and my XP bar went up accordingly.