I can't sync with steam, because it's saying that my profile is not public nevertheless it is public

"Please switch to a public Steam profile before attempting to sync. This can be done by updating your Steam privacy settings as seen below."

And on my profile: "Visibility of my profile: Public"

I don't know what the problem is, but a lot of users have been reporting the same issue lately. If you search the discussions for sync, you will find a lot of threads and maybe some answers.

https://www.steamgifts.com/discussions/search?q=sync

Hi, that problem has been reported a lot of times already...
basically just try to sync a bit later... it seems to sometimes not work and after a while its working again.

Happened to me after I updated Chrome. Clearing the cache and restarting the browser is what helped.