Hello,
Are you collaborating on this project using BIM 360 Design and Revit 2019.1 or Revit 2019.2 ?
If that’s the case, you should be able to link an IFC file using the Desktop connector as explained in this video
https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/video/youtube/watch-v-cyWQ8...
If you are using Collaboration for REVIT (C4R), the issue you describe seems similar to this one:
https://forums.autodesk.com/t5/revit-cloud-worksharing-forum/c4r-how-to-link-ifc/td-p/5789172
Could you test the suggested solutions and workarounds.
Does it help ?
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Regards
Guillaume Chazal