Created a giveaway and got 1 entry didn't changed your contribute value?

Yep. That's how it works.

I not 100 % sure on that matter but GAs with 1 entry don´t count as GAs but rather as giving a gift.

num gifts +1 is the minimum to get CV as I understand

so if its a 2 copy, you need three entries to get CV and so on

Otherwise You could just give Your friend a game and get free CV. That would be cheating!

On a related topic: A person from a giveaway-group I´m in seems to be loosing slots from 0-entries or 1-entry GAs. Any reason why that would happen ?