Export of 'Presentation' does not contain any Textures brough across via Direct Link from Revit or any Custom Textures.

Specifically, with Twinmotion 2023.1 for Revit 2024. The materials appear correctly in the Twinmotion editor, but the entire model appears white in an exported Presentation EXE file. If I replace a material with pre-build Twinmotion material this DOES show in the Presentation export - I’m guessing custom textures are not being collected/complied during the creation of the Presentation correctly? I’ve tried manually re-pathing the textures (to both the same and different files) on my desktop, but exports still result in a white model. Is there something obvious I’m missing?