iPad - invisible icon

There’s a Facebook app on my iPad - when I search for it, it shows up, in a folder, and the Apps app shows that it’s been installed - but I can’t locate it on the iPad. I can run it from the search results, but it’s not in the folder where search shows it to be, so I can’t run it by tapping on its icon.

I’ve seen the advice to turn off the remove-unused-apps setting and the advice to restart the iPad, but neither of those makes the icon appear.

So my question is, how do I get the icon of the Facebook app that has been installed on my iPad to become visible?

All suggestion greatly appreciated.