@RMA - It looks like the issue around the missing ‘Title’ field is related (for me at least) to the inclusion of the develop history within the jpeg metadata.
Try going into the ‘export selected’ module in the lighttable and clicking on the cogwheel next to the export button. Deselect ‘develop history’ and try again. Does it work now?
Edit: I think the Title field might actually be present in the metadata (since Geeqie displays it if I use it to view the jpg) however, if I try to extract metadata using exiftool (on the command-line) or libxmp (via python) neither tool can see it. The one image I have an issue with has quite a big history stack so that might be a contributing factor.