games i already own not hide

Have you synced your account since obtaining those games? If not then there's your problem.

some collections show up cuz of steamid ...another example is tropico 4 collectors edition . Hide them maually one by one for now. till it's fixed.

Hiding games you already own will not hide DLC, mainly since steam can't tell steamgifts what DLCs you own. So any DLC or a package with both the game and some DLCs will still show up. Just hide them manually and it won't be a problem.

Packages and collection aren't reported correctly as owned by Steam so the site can't know that you own them. Just click on the little eye icon on the right side of the giveaway name to manually hide it.

It doesn't seem to be hiding anything I own. I opened the page for a few of the games I knew I had, and it shows as existing in my account but it's not hidden from the search. So now I have 47 pages of giveaways to sort through If I want to check them out.