Hello
Here are some steps and suggestions that might help you resolve this issue:
Kiosk Mode Setup: Follow the steps to set up Kiosk mode correctly. Go to Settings > Accounts > Family & other users > Set up a kiosk. Choose the app you want to use in Kiosk mode and follow the prompts.
Surface Pro tablet - Kiosk - Microsoft Community
Repair Microsoft Edge: If you are using Microsoft Edge in Kiosk mode, try repairing the app. Go to Settings > Apps > Microsoft Edge > Modify > Repair.
Error in Kiosk mode - Microsoft Community
Troubleshooting Steps: Verify that the configuration XML file is authored and formatted correctly. Correct any configuration errors and apply a new provisioning package.
Kiosk mode issues troubleshooting - Windows Client | Microsoft Learn