It's possible that your CPU is faulty, but there are also other factors that could be causing the stability issues you're experiencing.
First, you may want to check the temperature of your CPU during stress testing. High temperatures can cause instability even on stock settings. Make sure your CPU cooler is properly installed and functioning correctly.
Next, you could try updating your motherboard BIOS to the latest version. Sometimes BIOS updates can improve stability and performance.
If those steps don't resolve the issue, then it's possible that your CPU is indeed faulty. You may want to contact the retailer or AMD support to see if they can help you troubleshoot the issue further or potentially replace the CPU if it's still under warranty.
It's also worth noting that every CPU is unique and may require different settings for stable operation, even on stock settings. So, even if your previous CPUs worked fine with the same RAM and motherboard, there's still a possibility that your 3700X may require different settings to operate stably.