small bug(?) in exporting COLMAP database

[oUp2Uo]

Hi, recently I am trying SFM disambiguation which will need to edit COLMAP database, and I find that the exported COLMAP database has different columns when using different images.
Sometimes qvec and tvec is exited (this is normal situation).
But occasionally, there are no these two columns, while running the same commands but using different images.
Although these values are all null, but some other programs will read these columns when loading COLMAP database.
I try to add qvec and tvec manually and it works.

I have tried to check the source code, but still could not understand why qvec and tvec columns are gone.
Maybe is the difference between calling add_matches and add_raw_matches?
https://github.com/3DOM-FBK/deep-image-matching/blob/master/src/deep_image_matching/io/h5_to_db.py

Thank you.