The answer is, I was close to the top of the TFR (1,500) when I saw it
at first. I was at a somewhat higher altitude on the way out so the
display of the TFR was suppressed. Very nice but I need to do some more
training on the 396.

Maule Driver wrote:
I flew into and out of 3W3 this weekend (to eat crabs). 3W3, Kentmorr
Airpark, is a grass strip underneath the Wash DC ADIZ that has a
specific procedure for ingress and egress.

Managing the procedure and airspace restrictions was easy with the 396
and my 300XL. Flying in from the north, I noticed the Cheny TFR was
marked on the display - a 1 mile PFR over St Michaels MD. Cool! However,
when I left 2 hours later, it was gone. I knew roughly where it was
supposed to be and flew around it but I could no longer see it on the
396 display.

Has this PFR turned into a true TFR and was the Garmin accurate? Or is
there some problem with the unit or my operations?