Flickering horizontal lines on new MacBook Pro 2021 M1 16 inch

I took receipt of my new MacBook earlier this month, but it has suddenly developed a fault today where there are flickering lines across the top of the screen that run from one side to another (see videos: https://youtu.be/o0-CilEOCNs and https://youtu.be/FiTinyB7sOc). The lines aren't always in the same place and can appear further down the screen, but always horizontally.

The MacBook hasn't suffered any trauma. I ran diagnostics and the code said there were no hardware issues, but I could still see the problem in recovery mode - which I read could mean it is a hardware issue.

I know some issues can be caused by software, but is there anything else I can try before I surrender it for repair? Unfortunately, where I live I will need to courier it as no Apple Centre near me. I have already reinstalled Ventura OS and that didn't help. Thanks in advance.