You shouldn’t be crashing at stock settings, throttling maybe but not crashing. I assume you have done cmos clear? And is this a fresh windows 11 install? Have you tried in safe mode by chance? Updated to the latest motherboard bios?
Is the CPU within its return period? Might be worth it just to be 100% sure. If not and you need to go through an RMA with Intel. Try running the Intel CPU Diagnostic Tool. https://www.intel.com/content/www/us/en/download/15951/intel-processor-diagnostic-tool.html even if it passes it doesn’t 100% mean it’s your CPU. And Intel will request you run it prior to RMA (at least in my experience) only takes a few minutes so might as well give it a go.
Z690’s are fine on 13/14th gen. I had a Z690 Hero and it’s a great board, even more so with the recent price drops.
I will say that Z790’s, at least mid to higher end ones due tend to do better with 7000+ memory speeds. I could only get 6800 stable on my Hero. And I tried my tail off to get higher. Mind you it was my first time overclocking DDR5. So maybe if I had more experience I would have been successful.
For about the same price I would recommend at least taking a look at the Asrock Z790 Nova WiFi. Pretty good bang for the buck board. There is a thread over at overclock net and it’s getting a pretty positive reception.