Hi MoJasir T V,
Thank you for reaching Microsoft Community. We appreciate for sharing your concern to us.
Would you please provide me with the brand of the protective case you used? You can send us the link here.
Are you using the Surface pro X keyboard or the Surface Pro signature keyboard?
It's possible that some protective cases won't work with our Surface devices.
We look forward to hearing from you.
Kind regards,
Lavenia