Currently I have the sensor covered with 2" x 2" Post-it notes.
A single layer was definitely not enough, so now I have a double layer of pink post-its and they happen to be sort of tweaked so they lie almost cupped around it, even though they are only stuck at the very front. It helps, but isn't quite enough yet.
I'm afraid to try anything more permanent ... I read somewhere a suggestion of marking it up with a black permanent marker! ... but I'm not prepared to try that yet.
There are enough people who are frustrated with it that I don't understand why the engineers haven't found a workable solution yet!