Symptoms
When checking the list of domains assigned to the particular IP address in Plesk > Tools & Settings > IP Addresses > Sites link, the Home page is opened instead and the following error is displayed:
Error: Invalid URL was requested.
Cause
The issue is caused by the bug with ID PPPM-13921 which has been fixed in Plesk Obsidian 18.0.51.
Resolution
Update Plesk to the latest version.