Step by step instructions to Clear Instagram Cache

Open the “Settings” app on the iPhone
Go to “General” and then to “iPhone Storage”
Wait for all storage data to load
Scroll down to locate the app list and find “Instagram”, next to it will be the total storage size taken up by the app
Tap on “Instagram”
Tap on “Delete App”
Confirm that you want to remove Instagram by tapping “Delete App”
Now open the App Store on the iPhone
Locate the “Instagram” app (using Search or otherwise) and download it again