Question about Robomow RX20u

Using a robotic lawnmower on an underground garage is risky and therefore not recommended. The iron content of the garage can interfere with the functions as an interference signal.

It works perfectly for us on the garage roof

Iron does not interfere, ours drives over concrete slabs with iron bars in them, it is an induction loop that is placed around the edge of the lawn, this is under low voltage, only therefore it can be detected by the robot at all.