Karnakanti, Saideep Thanks for reaching out. It seems like you're experiencing an issue with the new Logic Apps designer where the details of action items, such as the SharePoint "Get Items" action, are not loading and only showing a loading symbol. Could you please confirm if it was working fine before? Sometimes, clearing your browser cache can resolve loading issues. Try clearing the cache and then reloading the Logic Apps designer. If you are using a specific browser, try using a different browser to see if the issue persists.
Can you also check the browser trace/console logs to see if there are any failures? you can also try testing the same in older designer use this url https://aka.ms/lafallback to rollback the logic app designer to older version, please try and let me know if issue persists in older designer as well.
If you're facing this issue only with the new designer as mentioned in the above tech community blog i would request you to open an issue in our GitHub repo: https://github.com/Azure/LogicAppsUX.
Hope this helps! please let me know incase of further queries, I would be happy to assist you.