If you setup your Facebook Page in the Facebook Manager, than it removes access from the from the regular or personal Facebook App. The Facebook pages app has a lot of bugs lately. You can't do basic things like post, view notifications or really do much of anything.
This tutorial will walk you through how to get access to your regular personal Facebook App so you can manage your Facebook page withing the personal app. This method does not remove access from users with existing access and will also allow them to manage the page from their personal Facebook accounts. This is different from Merging accounts and will not delete any data if done correctly. I have only tested this on IOS.
If you're like me, than you spend most of your time on Facebook in the app and this makes it easier to share articles and comment on posts without having to copy and paste into Facebook Pages App or login to a desktop.
How To Add Access To Your Facebook Business Page In Your Personal Facebook App
1. Go to your desktop Facebook account on your desktop and on the right-hand side click Business Manager > Your Name
2. Go to upper left-hand corner and click the drop doewn > Select Business Manager Settings
3. On the left click Pages.
4. Select Your business name and then click remove. This will not delete your page, just remove it from the Facebooks Business Manager. Pages within business manager can only be accessed on a mobile device using the Facebook Pages App.
5. Confirm that it's ok. If you use the page within business manager thn you may not want to proceed. However, I'm not sure exactly what the benefits of keep thing page in Business Manager is. It appears that you still have access to the Ad accounts.
6. Once it's removed, you'll need to add the page to your IOS device Favorites to make it easy to access. Go to your Mobile device and open up the regular personal Facebook App. Click on the hamburger menu in the lower right-hand side. You will notice that your page is not available yet in the list. Don't worry, you just need to add it.
6. Click the Pages option above and it will take you to the Owned Pages view. You should see your Page there now. Click on your business page.
7. Now, with you page open, click the 3 dots in the upper right-hand corner to open the settings options. Click Edit Settings > General
8. Under Favorites > Remove Page From Favorites & Immediately Add Page To Your Favorites. This will reset and add the page to the Favorites menu again making the page easy to access.
9. Click the back arrow in the upper left-hand corner till your back to the home menu to confirm that your page is there.