[Elecraft] more AGC/S-meter questions

[NZ8J]

For some reason now I can't seem to get the S-meter calibrated, or at least
it won't stay where I put it. When I do a S-LO, I set it to just go out...
then when I hit menu to go back to the freq readout, the s-meter will jump
up to about mid-scale.. All this is with no signal input of course......

Also, what is the proper frequency and bandwidth to use to calibrate the
S-meter?  There seems to be a big difference when I use the SSB filter vs. a
cw filter

thanks
Tim
NZ8J