So been looking around to a solution to this problem but have not found anything conclusive yet. The picture explains the issue, I get these odd blasts of colour artifacts in my render in some frame, I tried adjusting the light threshold but has not seem to fix the issue just moved it to different frame, should not this does not happen in view port render only final render. Could anyone explain or help with this?
AMD usually has those kinds of problems. Results should not depend on output resolution.
Regardless of whether you have an AMD card or not, you try to update to the latest available graphics driver. And if the problem persists, you should report the problem on developer.blender.org for which you should share a scene where developers can reproduce the problem.
it looks like a light source in a volumetric medium. is the light source possibly set to hidden in the viewport but visible in renders? also volumetric point sources tend to become better defined at higher sample counts (as is the case in your 128 render samples vs 32 viewport samples).
Have you looked at using any of the Light probes for eevee to see if that helps? EEVEE has some weird limitations and those probes can help and I would try to increase the shadow map size. Rendering productions level images in EEVEE is a bit complicated and involves a lot of tweaking. Maybe try Cycles?
Any head way with this ?
Having similar issue, mine is with an animation.
Noticed the OP said having issue rendering in HD (doing the same 1080) but when dropping to 720 (which i didnt try) the issue goes way; when i render my full timeline 1735 frames the issue is present, but if i only render 1-400 frames (which is the problematic part) the issue does not happen.
Heres the thread i started with alittle more info and example video clip.