Registration question update caused approved attendees to re-register

[CAASAZoom]

Hello-I set up a webinar with custom registration questions.  About a few weeks before the scheduled webinar, I changed the wording on the questions.  Confirmation emails were sent one week, one day and one hour before the the webinar. The day of the webinar, attendees got a message that said "Register for this webinar.  If you've registered for this webinar or have been invited as panelist, join via the link in your email invitation or sign in to your account, with the "Register" button below the message. Eventually, most folks figured it out and got in. Since I did this with two future webinars-can I expect the same issue will occur? If so, how can I guide the attendees to lessen confusion and frustration.  Thanks in advance for your time!