How can I remove free standing app icons on my iPad?

I have just got an ipad gen 9. I am creating my usual groups of apps - navigation and weather similar to my iphone but with two of the apps although I have dragged them to the group they have also remained free standing on the home screen. If I drag the free standing one to the app library or another page it disappears from the group. How do I clear the free standing icon from the home screen but leave it in the group where I want it. (both these apps go into groups fine on my iphone se gen2 with out leaving the copy icon)

[Re-Titled by Moderator]