I have checked my settings too. I've enabled overlay both in the universal settings and the specific game settings. But the achievements still doesn't pop up in game

Any way to solve it?

Press Shift+Tab while in-game.

• If nothing happens, then the overlay isn't working. It could be that the game doesn't support it or it's broken by an external utility like RivaTuner.

• If a chat window pops up, then the overlay is working. In order to unlock achievements, the game executable and the GOG Galaxy executables must have Internet access. Be sure to test with a very easy or unmissable achievement. The game itself might be buggy; check if it's on the list of broken achievements.

I got some weird things since last year.

Two examples: in Castle on the Coast I had one of the orb-related achievements unlock across saves and the last one I need, "Orb Seeker" doesn't unlock because I already have the higher tier one (collecting every orb in the game).
I have no idea what to do now.

Another weird thing happened to me when I started playing Montezuma's Revenge after the update. I finished world one and Galaxy shot me up at 100M completion, now I cannot unlock the rest of the achievements.