Why in the good world are people comparing freaking Romario with Dembélé? Those are two totally different personalities, players and cases. Makes no sense. If anything such behavior (occasionally coming late) is nothing new. As I wrote earlier, Neymar, Piqué and others have had as many if not more (Neymar) such incidents without the local media making much fuss for obvious reasons. They were much more established players at the club. Dembélé is that strange introverted foreigner (Black too) who still struggles to speak Spanish so he is easier to bully in the media.
It's totally incredible that the destructive local media (I wish that they would speak about the lack of a sporting project for years, the hypocrisy of not criticizing certain players regardless of what occurs, their lack of critical questions towards Valverde, the questionable transfer policy for years, the many scandals sounding the board etc) is doing everything, from day 1, to damage Dembélé directly or indirectly, rather than helping him this early in his Barça career.
Of course he should be fined, talked to (seriously) once again and other common sense reactions. However I really dislike hypocrisy and I will call it out when it occurs. Sadly the local media (useless by large) refuse to do so.
Speaking about behavior, I really wish that they had given more space to dealing with/reacting to Suárez's on-field behavior towards his teammates (Dembélé) etc. and his damaging gesticulations and body language not much different from C. Ronaldo when at his best in this department. But of course that is never going to happen. It's Suárez after all. The established senior superstar. Not Dembélé.