Cannot use mdi:motion-sensor-off in a card

Configuration Frontend
1

Hi everyone,
I am trying to do a very simple thing to show some entities on a card and I would like to use these two mdi icons:
mdi:motion-sensor
and
mdi:motion-sensor-off

But I cannot understand why the first one is correctly shown while the other one is not.
I tried to clear the cache, use different browsers(firefox, safari, chrome), use different devices (windows PC, Mac, iphone, ipad) with the same result.

Any hint on what I might be doing differently?

2

Home Assistant only supports MDI version 4.4.95, which doesn’t have the ‘off’ icon. Your choice is from these icons https://cdn.materialdesignicons.com/4.4.95/

3

As said by @GordonTGopher, it is not in the Material Design list.

I believe the default icon in my config is ‘mdi:walk’
You could consider that one as “off state”.