Do you have light mass important volume, sky light, post process volume in your map? if so, are they stationary, static or dynamic? Did you try to build lighting? Looking at the image it’s hard to know what is going on with your setup.
Hey! Not sure about what hclement2 is trying to say but I can see plenty from this image.
Try bumping up light map values keeping to powers of 2, so it’s most likely 64, give 128 or even 256 a go!
Given the image though, I think the most likely suspect is something to do with overlapping UVs, what software did you use for modelling?