Spots on B&W 35mm negatives

Film FP4
Development: Diafine
(followed Diafine instructions)
Finish with Photo-flo

Looking at the negative on using a microscope, I was able to take a photo of it at reasonably high power. Judging by the microscope focus, it appears NOT to be on the emulsion side of the negative. It also looks like some sort of crystalline structure.

Long time peruser of APUG, first time poster.

I've got to add that, after looking at this negative in the microscope, it's a wonder I can make ANY prints at all. Actually, this spotting, first observed on an 8 x 10 print, is the first time I've seen such a clustering of these spots - perhaps because I just make so few 8 x 10's.

In my past photography life, I used single-shot developers. I wonder if my Diafine is getting just getting gunky?

Thanks
Jerry W