I just cleared the cache, and problem solved!
I'm of course a bit bummed to see 0.10 BTC "disappear", but I'm happy that my account now shows reality.
But one last question: does these kind of bugs happen often? It feels like I was the victim of an "illusion" somehow, and I'm wondering if I was really owning an extra 0.10 BTC or not?
Sorry, I'm quite new in the game!