HQ Losing XP?

[LordOfPants]

I had an HQ with 1 experience level showing. An attached corps attacked an enemy unit, and the corps went up to level 1 (dot on the counter) while the HQ went down a level (dot on the counter went away). Looking at the HQ it didn't lose a full star, just most of one. If it matters, this was a Hungarian HQ and Corps, HQ has no upgrades corps has upgraded IW 2, AA 1 MV 0.

What would cause this? Do units draw XP from their HQ when they level up, or is there something counterintuitive about HQ leveling?

[Sugar]

Units gain xp by any fight, HQs by winning battles. Even a draw is decreasing xp.

[LordOfPants]

Is 'winning' doing more damage to them than to you, or does it need to be a 0-X result or force a retreat? That makes sense though if they use different criteria for leveling up.

[Sugar]

Is 'winning' doing more damage to them than to you

Yes, own losses don't matter, as far as you're doing more damage than receiving. If you have to fight with negative predictions (for deentrenchemnet p.e.), you might deattach the unit from your HQ before.

[LordOfPants]

So the HQ should sneer "I'm not going to associate with cannon fodder scum like you," and just lead the units that aren't supposed to die, got it But seriously I think that's what happened, my corps was expecting a 1-2 but got something like a 2-2.