I have the same problem with this model.
I tried thunderbolt 3 to DisplayPort 1.4 adapter, but vertical bars exists.
I have 2 theories :
First - Thunderbolt to DisplayPort adapters are only DP 1.2 version, but no 1.3 or 1.4, Can anybody confirm have adapter with 1.3-1.4 ? You "just" need TV with 8K or monitor with 4K, but > 60Hz (exampl. 90, 120, 200 Hz).
Second - our laptop Thunderbolt 4 DisplayPort has only Intel video card output, because Nvidia output are dedicated to HDMI output, and we cannot get rates more than 4K to output on Intel Iris xe on thunderbolt. I will check it, because i have LG thunderbolt monitor with 5K resolution.