Had to recruit the help of @Jon here for a sanity check 
Looks like this is actually to be expected - Our node will write the JSON table to the CSV file, but in this case the table is just one row with all of your data in it.
If you were to attach the Spreadsheet node directly after the Sheets node, it would create the CSV file properly – but our node currently only handles comma separation. So if you wanted a ; option the best option would be to write it to a file using the execute command node to add it to a file locally, then a read file node to pick it up again.
You may also want to add your voice to this feature request here and upvote it: CSV spreadsheets with delimiter ;