I’m using a diamond tipped nozzle, 0.4mm. I understand that smaller nozzles like 0.2 don’t play well with filaments filled with solid materials, and the glow stuff suspended in this is indeed a solid material.

Temperature may be an issue, but I wouldn’t know. I print PLA typically at 230° C, including this filament, which I am certain many people will find jowl-flabberingly appalling but that’s what I do. My machine goes pretty fast and I found that gives me the best results.