Well, read the other threads and it seems like it's not possible.
Maybe this is a good thing. Will be able to finally give Vivaldi a chance.

It must be on the servers. Maybe someone from Opera could get it back? Can't I contact support or something?

No, it was all on the cloud.

Hi, like the title says. I forgot my pass phrase and reset my sync thinking it would keep my old data. No it's all gone and I only see the data from my new setup. Over 5 years of favorites, history and passwords, gone. Is there a way of getting them back?

I mean, why would you disable such a good feature?!
There are not even any expansions that let you do this...