Navigating to the project list (or other page list) in Classic Clarity takes longer than expected when you add more than 10-15 columns to the page view. If you update the column list to only contain 10-15 columns, performance improves.
This is working as expected. Best practice is to only have 10-15 columns on a list otherwise performance can slow down.
Release : All Supported Releases
Component : CA PPM SAAS INSTALLATION AND UPGRADE
Reconfigure the column list to be less than 10-15:
Option 1: You can update this for all users via: Administration->Studio->Objects->Project->Views
Option 2: To make this change just to your personal list view