I just bought a Breville Bambino Plus, and when I tried to lock the portafilter in the group head it doesn't turn and lock. There seems to be too much resistance to the point that I think I might break something.
I removed the ground coffee, then tried hooking it in again. I got the same result. However, when I removed the filter basket from the portafilter I was able to turn and lock!
I was using the same tools provided with the machine.
I'm not sure if the reason is the basket or something else.