I come across this at least once a month. Someone says they’re managing a Facebook business page but for some mysterious reason, it doesn’t appear publically unless the visitor is logged into a Facebook account.
Typically it has to do with Country Restrictions or Age restrictions. At some point, you or another page administrator/manager/editor had changed a Facebook Page Setting to limit who could see that page.
The fix is easy. Simply login to Facebook, navigate to the business page, click the page Settings.
Or try this URL: https://www.facebook.com/YOURFACEBOOKPAGENAME/settings/?tab=settings
If you look at this screenshot below, simply find the Country Restrictions and/or Age Restrictions and remove any entries.
I hope this was helpful.