Link to External Data Broken?

I’ve been having problems linking to a CSV file in a spreadsheet I’m working on.
Sheet > Link to External Data, browse for CSV file, choose options in Text Import dialog, tick “Update every:”, select 60 seconds.

Initially it seems to work. The data from the external sheet appears in the sheet I’m importing to.

However, when the update happens, things start to go wrong. It looks like the data from the external CSV file is imported into the sheet, but is put in a random place. So the data that should be in cell A1 appears in N23 (for instance), and the rest follows.

Am I doing something wrong / missing a step / somthing else?

LO 7.0.3.1.(x64), Windows 10.