Hello,
I have the same problem, with vaccum cleaner, microwave oven and dryer machine.
From firmwware 0.10.2 they SILENTLY added a more strict voltage control which cause this (talked to support)
There is no way to downgrade firmware
Product is crap now, there is no solution.
Hope they will do a step back
Any1 interested in 3 Shelly 4 PRo PM for sale sale sale?