Hi siddhartha pathak,
Thank you for reaching Microsoft Community. I understand that you are trying to connect a total of 3 external monitors to the Surface Laptop Studio which worked fine at first but now getting some display issues.
As much as we would love to assist you on this, but the external monitors supported for Surface devices are only up to two external monitors. Yes, there are reports where users are able to connect and use three external monitors, so we'll leave this post open for now to allow other users to share their experience and inputs on this concern.
You may also check this page for reference in connecting Surface to external displays: Troubleshoot connecting Surface to an external display - Microsoft Support
Kind regards,
Marrion