You’ll need to provide a little more information about the nature of the problem.
How did you introduce your “custom App icon” to your Home Screen? Does the App icon relate to an installable App from the App Store - or is something that you have created? Where you experimenting with the Shortcuts App - possibly installing a shortcut icon?
Posting a screenshot here may help you to both explain the issue in sufficient detail - and for contributors to better under the problem.
Before posting a screenshot, be sure to redact any personal or sensitive information using the iPad’s markup feature.
Take a screenshot on your iPad - Apple Support
You can post your screenshot using the image button at the bottom of the message window: