I have Amnesia A Machine for Pigs on my Steam account but I can't get it on GOG Connect. I refreshed four times and it still not showing up. Anyone has this problem?

Yes, there's already I believe five threads, including the Sale thread discussing this.

If you give me a few minutes, I'll be happy to link to them for you.

While you're waiting, you may want to take a look at the front page of the forums located here:

https://www.gog.com/forum/general

and skim looking for titles mentioning connect or the sale.

edit: Discussion and a suggestion here:

https://www.gog.com/forum/general/introducing_gog_connect_8fac8

Same situation:
Primary Steam account
GOG Connect results

Note that the full game list of my primary Steam account will take a while to load, not to mention there appears to be an incompatibility issue on some browsers that won't allow the list to display.

I got Amnesia A Machine for Pigs after switching my Steam account privacy settings. Thanks for all your help.

Seems there may have been some privacy issue on Steam that was preventing people from being able to see your Steam Library, even if you had it set as public. I started a thread about this on Steam here, I would assume this thread (possibly others) was what brought the issue to vALVE's attention, seems it got fixed fairly quickly after (literally got fixed as I was typing replies & edits to post #2 in that thread).

Me too.

It's not great anyway, don't bother.