Burn spot on EGR vacuum modulator filter

I was cleaning the little round filter that sits under the top cap of the EGR vacuum modulator on my 1999 Toyota Camry.
In the process, I noticed a little round burn spot about the size of the head of a pin on the bottom side of the dense gauze type filter.
Somewhere online I read that this little burn spot is an indicator that the diaphragm has a small pin hole in it allowing hot exhaust gasses to burn the underside of the filter.
I'm wondering if this is true and if I should replace the EGR Vacuum modulator.
I am not getting any kine of check engine code at the moment, so I'm wondering if I should just ignore this.
Has anyone ever heard of such a thing concerning this burn spot?
Thanks,
Harkauto