Like I said. Sterling was far worse. He was late to things, he was on camera huffing illegal substances, he was in court (and spent time in cells) twice for domestic violence charges, the reason he ended up at liverpool In the first place was because Spurs, Arsenal and chelsea all passed on him because it his behavioural issues.
Sancho misses breakfast and now hes so much trouble no one should sign him? Laughable.
The only reason we have heard this in the first place is that Favre and him have fallen out, Favre put him on the bench vs. Barcelona and Sancho embarrassed him by being the best player on the pitch when he came on, leading to Favre getting pilloried for not starting him and hes leaked an excuse to the german press to lighten the pressure.
I would treat these rumours with as much respect as the liverpool outrage over Sterling doing interviews without permission. Watzke, the dortmund DoF immediately came out and said there were no problems with Sancho.