Blotchy/Streaky GI artifacts even with high settings

For the past few days I’ve been rebuilding my lighting and changing settings trying to fix an issue I’m having with artifacts from what I assume is the indirect lighting. Attached is a screenshot of what I see when I am viewing the lighting only. There are random weird artifacts appearing like blotches or streaks. I have changed every setting I can think of, cranking them up pretty high, but nothing has solved this problem.

I have increased the Indirect Lighting Smoothness to 1.5
I have decreased the Static Lighting Level Scale to .15 and increased the Indirect Lighting Quality to 6.5
I have unchecked Compress Lightmaps
All of my lightmaps show up high resolution red when viewing Lightmap Density
Scalability settings are all Cinematic with Lighting Build Quality Production

What can I be doing wrong here? I am having the lightmap UVs auto generated by Unreal and looking at them they seem like they are fairly well flattened and packed and should be good enough.

This is being lit from an HDR (set to 2k resolution in the texture settings) and I have many stationary spotlights in the scene as well.