Hey there! Classic texture baking, never works on the first try right?
Initially I was thinking this could be an issue of ray distance, but that consistent triangle pattern has me curious. 🤔
To help give me a better idea as well, could I get you to provide:
– Screenshot of the the entire UVs
– Closeup screenshot of the UV island for the problem area in your original post
– A screenshot of what the normal map looks like
– Closeup screenshot of that area with the high poly and low poly overlapped with different coloured materials (like the image below, just so I can see silhouette difference)

I know that’s a bit of an ask but it will help me rule some things out at least! 🙂