I think to have found a little issue.
If the "Secret" (that is used by PPP to generate the Sequence Key) contains a single or double quote (
"), then the Sequence Key will not be OK to generate a valid passcard on GRC. Although GRC will create the passcard, the passcodes will not be recognized by WordPress.
Try to use a Secret like this:
I like to eat 'icecream'
either with single or double quotes.
Perhaps the quotes are to be escaped?