i was a lvl 3

This kind of stuff happens from time to time. There is only one person manually adding games to the bundle list and sometimes there is a delay. Get used to it :)

Levels should never be removed (you didn't contribute less than others, if anything you contributed more. You made a giveaway before the CV was reduced).

Except the value is only decreased during bundling if you gave it after it was bundled / heavily discounted. The value will be retroactive. It stops people exploiting things by rushing to beat the bundler.

If they gave before the bundle date, it remains untouched by the bundle status.

Bundle games are only retroactively added from the date the game appeared in a bundle, as long as you have given the game away before it appeared in a bundle, you wont loose any C.V.

Following your logic everyone would be doing mass giveaways immediately after any bundle is released to get full cv before the games are added to the list.

There's two reasons why levels have to sometimes drop:

1. Bundles. Newly-bundled games have to be added to the bundle list manually. CV is always going to be a somewhat handwavy thing given the complexity of prices, regions, sales, etc, but it doesn't make sense for someone to spend $3 on a bundle and get $100 worth of CV from it, and the only way to prevent that is to add them to the bundle list retroactively.

2. Price changes. This is more of a limitation of steamgifts. SG can't really store every possible price point that every game had at every point in time; it relies on retrieving the price from Steam instead. So when prices change, you lose CV. This I'd agree isn't technically fair, but there's no easy way to avoid it and, again, CV is always going to be hand-wavy and imprecise, so there's not much to be done about it.