Thank you very much. You are very kind.
This week I will try to apply some rust treatment solution. After that I will try again to remove the bearing.
The strange thing is that when I remove both wheels (rear and front), one bearing (magnet side) remains on the wheel, the other remains stuck in the middle of the axle brake.
The wheels are plastic version and probably the bearing spacer is not present as it is replaced by a groove inside the plastic rim that allows the bearing to remain motionless and pressed on the wheel / hub.
Another test I’ve done is to remove the bearing (the one that stays on the wheel) and push it (by hands) on the axle. But it can not slide on the axle and stops shortly after.
It’s very strange.
I’m missing just one thing. Can you tell me what is the bearing spacer usefull for? It is fixed inside the hub? Or it is fixed on the axle and the wheel bearing pass through on it?
I also believe (as you said) that the bearings have to be stuck on the hub and not on the axle.
As a final test I will use a bearing external puller and hope it will work.