The glow comes from the bloom. HDR just makes sure there are values higher than 1. Bloom is applied to everything higher than that. So there are 2 possible errors: Either HDR is not working on the device, or the bloom is not working.
I’m testing Particle systems on iOS (iPhone 5 specifically). I’m unable to give emissive glows to show for particles. In the Mobile Preview there is the glowing effect I expect, but once I package it for iOS and run it on iPhone the Materials no longer have any emissiveness/glow to them. (Mobile HDR is enabled). Is this not supported?
Do I need to enable the bloom anywhere for packaging?
Figured it out, in your device profile configuration you need to add:
+CVars=r.BloomQuality=1
for more info on config files.