When I add a tag to an image, the sidecar file is updated as expected. However, if I change the name of a tag which has already been applied to an image, the sidecar file is not updated. Settings Use lazy synchronization = OFF Read from sidecar files = ON Write to sidecar files = ON (Write to XMP sidecar only) Select an image in thumbnail view. Create a new tag "tag1". Click Apply. Exit DigiKam. Verify sidecar file includes "tag1". Start DigiKam. Select same image. Right click "tag1" and choose "Properties". Change Title to "tag2". Click Apply. (thumbnail shows tag2) Exit DigiKam. Sidecar still contains "tag1". If you do "Album>Write Metadata to Images", the sidecar will update to include "tag2" as expected.
An additional problem which may be related. If you use the tag manager to delete a tag which is assigned to some images, the tag is removed from the images in the database, but the sidecar files are not updated with this change (i.e. the sidecar still has the deleted tag).
*** This bug has been marked as a duplicate of bug 370245 ***
Fixed with bug #370245