Thank you for the detailed explanation of the scenario.

First may I suggest you use the BIM360 / ACC UI (web) to confirm you have the correct permissions (especially MOVE permission, which corresponds to EDIT permission ) on the model of interest. Please refer to this guide: https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/How-to-check-cloud-project-permissions.html.

Also, may you use this guide to troubleshoot linking Consumed/shared models: https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/You-don-t-have-access-to-the-cloud-folder-error-message-when-opening-or-linking-a-Revit-Cloud-Model.html