It is happening because of the Jitter setting. Could you please try turning it down to "0" once.
You are showing us the settings for Inner Glow, but the noise is probably from the Outer Glow, which I suspect has its blend mode set to Dissolve.
Thanks Sahil. "Jitter" did it. So weird. Never noticed this before and I'm very fluent at Photoshop. I guess not!
I'm glad it worked out.
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