The UE4 FBX importer is designed to handle game workflows and it does it well. One of the reasons Datasmith exists is that we did not want to disrupt game pipelines by changing how the FBX importer works. Since FBX is not well supported in AEC/BIM (except for rare cases), we chose to focus on native workflows. Which is why we have IFC support showing up in 4.23 - which will be in previews in 6 weeks. You’ll then get all the Datasmith love - automated lightmaps, UVs etc. Also, the importers for Twinmotion and UE4 are completely different code, so there isn’t anything common between them at the code level.
I know AEC FBX files that do load fine in UE4, so it is more likely something specific related to what is in your file. You can log a support request and submit your file if you want. Most likely IFC in 4.23 is the answer.