If You don't mind, I'll explain few details.
Your screenshot shows QCd Base Reflectivity from NWS, we're actually using QCd Composite Reflectivity. Its source data (that also NWS radar page is using) is available here.

Unfortunately, the datetime You show (7/21/25 04:04 AM) is not available anymore (data retention is about 12h). So I can't verify, that it is the same issue as we know of, but I believe it is. We can verify next time it happens, if we catch the source data in time.

The issue we aware are of is this: NWS uses blue colors for high reflectivity, that are not part of the legend and we don't know how to interpret them. There was (most likely) similar situation last year:

I tried contacting NWS with question about the blue pixels, but got no response back.

We are currently working on new processing of raw radar data from NWS (instead of using national mosaic), that will most likely get rid of this issue, and many other issues.