Missing entries in the issue timeline after import from Gitea

I have transferred all my projects from a local gitea instance to a local gitlab instance. I used the import function for gitea projects.
After the successful import, however, I miss the entries in the timeline in the individual issues. Neither the references to the commits nor the other information from the timeline are included. Only the issues with the associated comments were taken over. The metadata, such as creators and labels, were also adopted, but the times for this information are not displayed in the timeline.

I can do without almost all entries in the timeline, but I would have liked to have restored the references to the commits.

Is there some way to get this data back, or is it possible to manually set the commit references over the API?

Has nobody noticed this problem yet? I’ve attached a picture to show the missing data.