The former, it’s not being imported at all.
In my example,
ID is my identity column.
GLIDEID is the unique column for the Glide app.
You can create new rows from within Glide app (the identity column and the GLIDEID update correctly). However, the problem is the identity column is not shown in the table and you cannot edit rows which were created outside the Glide app. When Glide resyncs the table, it shows the new row and cell values, but the GLIDEID value is shown as Null which doesn’t match the GLIDEID value in the app.
The other post had the same issue, but no fix. Another post mentioned, creating a sequencing column and updating it outside Glide, but this is not feasible. Currently, this makes SQL Server as a datasource unworkable in the app, as really it can only work as a readonly app.