In this article, you will know why its showing the Lead widget instead of the share widget on your share page or thank you page. This is because the Lead widget is the fallback widget so whenever someone views your share page without opting in to your campaign they'll automatically see the lead capture instead.
When you go directly to your share page and the lead widget is showing this is because you haven't signed up to your lead capture page. The share widget will only show if you have signed up and clicked the call to action button or the sign up button from the lead widget or opt in form. Without the email you used for signing up it won't trigger or let the system generate the referral link which shows on the share widget.