I have the same issue with a S&C and a Fitout model after separate room export.
Rooms are in the Arch models, I am the BIM support for electrical engineers. I can’t merge the models in Revit every week, so I use two separate visuals which works fine, but hard to understand.
Unfortunately it seemes to me, Speckle exporter does not support exporting rooms from a linked file yet!
@gokermu Please let me know if i am mistaken with the linked export!
It appears that the error in the image confirms that rooms are not being exported from linked models. Could you please share the source model with us? You can send a DM. We will review it to find a solution. Please note that this fix will likely only be released for the next-gen Revit connector.