The problem with autobalance is, that ppl get punished for other ppls behavior, leaving the game earlier because they are going to loose or they just don't want to be on the attacking-/defending site.
The last game for example, i was switched to the loosing team with no more reinforcements available. I just could have been kicked from the game which would literally be the same.
First recommendation is not to autobalance anymore on the last 2 objectives, objective/cache.
Second recommendation is to lock players on the server during the match so that they can't leave and join another game till the actual game is finished. In case they disconnect there could be a 3min timer to reconnect, otherwise there could be an additional penalty where they can't join for another 3min, 2nd time 6min, 3rd time 12min and so on which is resettet every 24h.
I know another game handling the problem this way and its working well.