I don't see anything special yet. No sale, no giveaway. Doesn't matter how often I reload the page.

edit:
Huh? When I visit the game page of Tropico 4 and click on the giveway link, It redirects to the front page and I suddenly see the sale and everything else.
https://www.gog.com/en/#giveaway

edit #2:
if I remove the #giveaway part from the link, I'm back at the plain old front page again. Strange.

That's exactly what I meant.
About six minutes ago, I clicked on my browser's GOG tab, saw the sale, the GA...logged in, claimed T4, went back to the store's main page - and all that was gone.

I had to use my browser's "history" to get back to the "more actual" main page with the sales and the GA.

Something's not quite right with GOG.

The situation is indeed weird, as it is automatically saying I claimed the game successfully, without having to click any CLAIM button. But alas it is nowhere in my library. I have Tropico games 1 through 5, with 4 being the exception, and they show and it doesn't.

I'm gonna try logging out and back in, and see if that changes anything, but the main GOG store page has been giving me grief for a while with the IN LIBRARY label not showing up, to show me what games I own, etc.

EDIT
I was able to resolve the issue in the end by using the Opera browser instead of Brave (Chrome clone).

And because my Opera install is pretty bare bones, I even saw a popup advert while logged into GOG, which is the first time I have seen any advert at GOG.