I found a fix for the issue I was having thanks to @Makigirl 's comment on another post.
"Hi!
Unreal when builds lighting it calculates lighting per object this is why you get with these settings shading differences! SLLS: 0.1 - 0.15 ILS: 0.6 and you’ll get rid of those!! 
…I would turn off lightmap compression (and AO too till you don’t get your lighting right). Also 100 bounces are pointless: above 10 it’s just random and can produce false results… just keep it between 5-10!"