Tuning Extra washer in regulator?

I took apart the regulator from my Avenger and found one more washer than the parts diagram for it shows. Should I leave it in? I’m assuming it was a mistake and planning to leave it out.

Mine creeps about 100 psi if I only fill to 3000psi. If I fill it to max pressure, it goes up to 3000psi overnight. I’ve polished out the circular marks that were on the delrin seal. I know the marks are responsible for the creep, but how would the extra washer effect performance?


 
A double set in same direction among opposing singles is NON correct within any reg configuration.

looking at what shown see 11 bevels and 11 works out just fine given enough room ()()()()()( this would be used with right side as shown at the smaller seat end of spool.

11 is one shy or one too many in a double stack being 10 or 12 (())(())(( +/- ))
 
The anomaly in that stack is the single nested pair bolded here: 

) () (() () () (

For the most part it is acting as a rigid cupped shim, and has the potential to invert and damage the single washer to the left, meaning this one:

) () (() () () (

My advice would be to ditch that washer (it may be compromised) and reconfigure the stack as a plain series stack

) () () () () (