They have failed to get Favor working consistently and reliably since launch. Every patch breaks it in a new and frustrating way. This is really starting to annoy me.

Same here. To add to this:

For some reason my achievements go all nuts when I play multiplayer.

- Getting weird achievements. I have played less than 10 games online, so it should be pretty impossible to max out the "Kill 500 DGs" Achievements. After the last couple matches I always had those maxed with the character I played. I turn the game off and back on and everything goes back to more or less normal.

- Achievements not locking properly. Since I've noticed the wonkiness of the achievement system, I played Unclean Beast a couple times and got the "Corpus Explodicus" achievement. It doesen't "stick". May be related to the above.

- Favor points not adding up. Since May 11th, I stick at 205 FP online and 750 FP offline - or rather, before I play online, my total is 750, after playing online (and earning participating/winning FP) it still goes back to 205 FP.

I hope that GPG is aware of this...

Both. As of 5/15, I am getting favor from neither Pantheon nor customs.

my favor is now stuck as well... yay...

At first I thought it is just now recording my wins at all, but as it record all my loss.  Then I thought it is just not recording because there is always someone leaving in mid game, so it count as AI battle aka I lose no matter what. Then I found out those 10~25 favors from losing a game full of people still doesnt add on.

God dam, wasted a whole day trying to get favor. This is really fucked up.

My favor points are also stuck. I would be really disappointed if they disabled favor points from custom / skirmish matches and used them only in Pantheon. I don't want to play 2v2 exclusively to earn favor. Please Stardock, let us earn and keep favor points for custom matches!