Atleast in one footage hamas fighters went back to collect souvenirs where they hit one tank with RPG earlier. There were no tank(destroyed or disabled) there by that time. It once again appears that they are not penetrating armour. I seen footages of Hamas attacking tanks from the rear and still no ammunition cook-off. Merkava ammunition storage is in the rear of the tank, so if it is penetrated, it should have caused a cook off.
Again, I am not saying that it's 100% certain that it's not penetrating the Tank armour. As of now, there is no opensource evidence that they have. This will play a great part in whether or not Israel can take Urban gaza without heavy casualties. If Hamas RPGs can penetrate tank armour, it make the job really hard for Israel. As of now, we don't see Hamas using any FPV drones, and it appears like they don't have any. Those RPGs are their primary antitank weapon and if Merkava armour can hold up against it, then advancing to City become much easier for IDF.