I am not sure which all suggestions that you have tried and therefore my suggestion below may be a repeat of something that you may have already tried.
The Find My app cannot be deleted and therefore it still exists on your iPhone. One place to search is in the App Library which is the last home screen when you continue to SWIPE LEFT until you reach it. Locate the Find My app in the App Library and then drag and drop it in your favorite location of your iPhone.
If the above, for some reason, does not work then you can open Settings ➔ General ➔ Reset ➔ Reset Home Screen Layout. This action will reset your Home Screen app icons and Find My should be on first home screen.
Axel F.