Problem with nvidia driver after last Ubuntu update

After last system update on Ubuntu 20.04.3 LTS (5.13.0-28-generic) my graphic card was switched from GeForce GTX 1650 Ti to intel one. I purge old nvidia driver and I re-installed the 510 recommended one. I selected nvidia graphic, from Nvidia X setting but always Intel continue to be used and displayed in settings.
Running nvidia-smi failure occurs: NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver.

Please run as root and attach the resulting nvidia-bug-report.log.gz file to your post.

here is the bug report in attachment.
Meanwhile I disabled secure-boot and everything came back to work correctly. Is there a way to make everything work with secure boot without re-installing the system?

nvidia-bug-report.log.gz (144.8 KB)

You can use update-secureboot-policy to achieve that.

Could you suggest some link with procedures to follow? Thank you