Blotches/artefact in interior archviz scene only on some objects

Hi guys,
I am pretty new to unreal and I am currently in the process of learning how to create an interior scene.
Until now everything has been going pretty smoothly until I have stumbled across an error I just can’t fix.
For some objects in my scene, there are weird artefacts/blotches that make those objects very dark.
I have already googled around and tried playing around with the lightmass settings and increasing the indirect lighting bounces, but that didn’t seem to fix much.
All objects in my scene have a high lightmap resolution, so that shouldn’t be the problem either…
As I am a beginner at unreal I think I might be just missing a simple setting that I haven’t heard of yet, but if anyone could help me out that would be amazing!
Here are some pictures of the problem and also the lightmass settings:

https://forums.unrealengine.com/core/image/gif;base64

https://forums.unrealengine.com/filedata/fetch?filedataid=155517&type=thumb

Thank’s for your reply!
I did check the Lightmap Coordinate Index and that was all set up properly, so that wasn’t the problem.
I will definitely check if they are set to movable… that would be such a dumb mistake to make haha just didn’t think about that!
And about the settings, sorry for that I think I somehow messed up posting the photos… I think the right one somehow got lost in the void!
However, after fiddling around with some settings I figured out that most of the blotches were fixable by changing the light build quality to production! It took a good while to build but it definitely fixed most of it! I also figured that some of the blotches were caused by some invisible objects that I removed somewhere along the project but unreal still renders them when it comes to building the lightmap.
I’ll attach some pictures of how it looks now!
Thanks a lot for looking into it!