Dear Vahnya,
There may be some temporary sync issue in your Power Automate environment. I suggest you remove the existing Get items action and then add it again to your flow to see whether the columns can be showed.
If the issue persists, some related screenshots of the issue are appreciated.
Note: Remove nay private information before uploading the screenshots.
Welcome to share any updates at your convenience.
Your efforts and time are greatly appreciated!
Sincerely
Cliff | Microsoft Community Moderator