Cel shading causes skydome problems

i follow their instructions how to do cel shading but the background mess up.

does it have issue in the level as well? what tutorial did you use? was it the one from the unreal training stream? if so theres a few solutions on the forum

https://forums.unrealengine.com/unreal-engine/events/1407662-unreal-engine-livestream-post-processing-in-ue4-cel-shading-jan-4-live-from-epic-hq/page2