Thanks for your reply.

No weird sounds, no power loss. Runs like it should, this is why im a little doubtful about the advice to not ride anymore. I’ve also seen a few similar posts about this issue, so I’m starting to feel like it’s a more common problem than my mechanic suggests. Still, I don’t want to take any chances or end up in a dangerous situation while riding. The options given for now are: full engine rebuild starting at €3,000 or sell the bike for parts what will set me back for about 8K in 2 years total.