Instagram not available among share suggestions in iOS 13

When I wish to share a Facebook post to Instagram on iPhone running iOS 13, Instagram does not appear among the Share Sheet suggestions, not even when I hit MORE... I have seen numerous how-tos about hitting EDIT and toggling on the applications listed under Suggestions, but Instagram is not listed at all, although I have the app on my phone and use it all the time. How can I add it to my Share options?