Redmine

Hello veryone,
I have setup a Redmine 6.1.1 server with a bunch of existing projects and now want to import a few hundred issues.

Everything seems to be coming along nicely, however, I am failing on the built-in batch issue import when it comes to parent task relation mapping.

I created a unique issue id starting from 100k to ensure no such issue exists already. And then I reference that CSV-internal, unique issue id and map it to "Parent Task" in the importer. I assigned that CSV-internal, unique issue id to the importer's "Unique ID" but that of course is not used for the Redmine's database unique id.

So the structure of the CSV is like this but with id starting at 100k and each Subject is unique.

Issue ID | Subject                | Parent Issue ID
1        | Parent 1               |
2        | Child 1                | 1
3        | Grandchild of child 1  | 2
4        | Child 2                | 1
5        | Grandchild of child 2  | 4
6        | Parent 2               |
7        | Child 1                | 6
8        | Grandchild of child 1  | 6
9        | Child 2                | 6
10       | Grandchild of child 2  | 9

The importer correctly assigns child 1 to the parent and grandchild of child 1 to child 1. But child 2 and its grandchild are not properly assigned.
For parent 2 I then see the same behavior, i.e. child 1 is correct, child 2 broken.

Does anybody know how I can fix this?

Thank you
Alex