Suspicious things in pirated euro truck simulator 2.

I got pirated ETS2 from codex, everything is fine but few things like sleep doesn't looks fine to me. Sleeping meter fills up too early (IMO) while driving (those who play ETS 2 may know what I am talking about), I was driving from Dover to Paris, I had slept before starting the trip, but I had to sleep again just after finishing it, actually I am new to ETS 2, I don't know how sleeping works, but I think this is not normal.

I doubt it's a bug, but I can't find anything about it on google, so I doubt, it's an anti-piracy measure, anybody please clear my doubt?