Receipt requirement at line is not working if we attach the receipt at header

We have given receipt requirement at expense template level with a threshold of 1000USD.

If the cash expense line is more than 1000USD, then a receipt is required and we have enabled receipts attachment at both line level and header level.

Now, if we attach a receipt directly at header level, without selecting receipt missing at check box, the report is getting submitted. Ideally, the report should not get submitted and show as awaiting receipts, correct or is this an expected functionality?