I had this issue in the Portal WAB seems the token was corrupted and displaying two of them.
Fix: Edit the App, removed the basemap gallery widget from the app > Save and clean cache refreshed the app to make sure it was gone. Edit again and re-added the Basemap Gallery > Save/clear cache / refreshed and it should work now.
Note: Removing and Re-adding may be enough to fix it just not the way I went about debugging it.