Was LV2 now I'm LV1 again! (Why are there no LV locks??)

Probably a game that you gave away got bundled or it got a price drop.

Something you gave away in the past was bundled so the CV you got from the giveaway was reduced by 85%.

Spooky.
The game got bundled

Because then people would rush to exploit recently bundled/glitched/free games like they do already - but gain permanent advantage from it.

I can kind of see both sides of it
on the one hand it means somebody who gives away something expensive loses the credit for doing so once the price drops
on the other hand it prevents people from buying cheap and getting credit for a higher price after a sale ends and it encourages consistency in giving rather than requiring a few one offs