Ravenlok

I also have the issue where the achievement isn't unlocking even after completing it.

I just asked Alexa while playing the game, she told me the answers. Learned some things I didnt know about frogs :D

@fr0gm4st3R @ShameOnAMonkk When answering, were they wrong in any question?

Just had it lock on me too.
Finished game, went back to the "Lilly Pond", Frog just says "ribbit"

On my playthrough, I answered all questions correctly 1st time.
All the achievements unlocked late for me (like 2-3 mins) only reason can fathom if its not happening to everyone, is that i used QuickResume throughout (never fully quit & played over 4 days).

BUT i was able to Unlock finally, without starting a new game.
Try exiting the game, hitting continue & using mirror to goto LillyPond, then walk over to the frog & wait.
For me, this didnt work, so fully quit game, reopened & went to New Game, clicked on my Save & gave the option "Load this save".
Clicking on Yes took me back to the LillyPond, (where i last was) and a few moments later the achievement unlocked ....feeeeww.