If a Facebook Page is unexpectedly not showing up among the options presented when connecting in Funnel, here's what to do:
User access
First, make sure that the Facebook user you are connecting with has access to the Facebook Page in question. It is important that the user you are trying to connect has a Page Role on the Facebook Page that you are trying to connect in Funnel, access only through Facebook's Business Manager will not be enough. Please follow Facebook's instructions on how to view your Page Role, and make sure that the user you are trying to connect is listed on the Page Roles page under one of the following Roles: "Admin", "Editor", "Moderator", "Advertiser", "Analyst", or "Jobs Manager".
Granular permissions
If this is the case, and the page is still not showing up, the cause may be "granular permissions".
To determine this, go to your Facebook settings (either Apps and Websites or Business Integrations) and click on"view and edit" for the respective app.
In the window that opens, scroll down to the section "Show a list of the Pages you manage", and put a checkmark next to all of the pages that you wish to have listed in Funnel.
You should now be able to find the missing page on connect.