What type of mirror glass do you all have?

I have a Pilkington Mirropane Chrome Spy and to me it seems that this type of Mirror glass interferes with the RCWL-0516.

When doing tests (mirror glass taken off) the sensor works as expected but as soon as I put the mirror glass back it stops working through the glass.
Waving my hand at the side still works.

Greetings
Michael