Establish what is happening
Identify columns by position
Record the source position, repeated label, and a distinct sample value for each affected column. Include neighboring columns to detect shifts. Keep the original header sequence intact; renaming columns in the source too early can hide whether the parser, preview, or mapping layer loses one of them.
Compare preview identity and mapping
Check whether both columns appear and can be selected independently. Record any generated suffixes and the underlying selection behavior. Two visually different labels do not prove the mapping uses distinct identities, especially if confirmation later resolves both selections through the original repeated heading text.
Inspect one controlled import result
Follow the two known values into their intended destination fields using a safe fixture. Determine whether one value is missing, duplicated, or assigned to the wrong target. Compare the final mapping with the approved preview before attributing the result to destination validation or a user selection error.
What to carry forward
Triage should end with source positions, duplicate labels, expected destinations, and the first loss of distinct column identity. State whether the product rejects the layout or silently accepts an ambiguous mapping. The next owner should be able to follow each value without relying on the repeated heading alone.
Technical background: DuckDB documentation.
Keep the decision with the work.
Use a Work Item in Aglet to record the problem, the evidence you have, and the next decision. Add an owner and priority, then keep updates in the discussion so the next person can follow the reasoning.
Create an account See the product workflow