Just so you know you're not alone, I came here to report the exact same issue. Using Chrome, APW adds one month to the expiry date on my credit cards. At first I thought it was my error and went into PW to edit my card details. When I saw that they were correct I tried a little experiment and went to the card section of a site I but from frequently and tried adding each of my cards using APW. Each instance added one month to the expiry date.
As I see you have already raised the issue and a problem has been identified with a resolution in play there's nothing else for me to do except to say "me too".