Is the US passenger attestation form a requirement for subsequent entries into the US?

The US has an entry requirement for UK residents (and other countries) that requires every traveller entering the US to fill in a passenger attestation form.

I had successfully entered the US November last month (having filled in this form) using Delta's online travel-ready form.

I am travelling to the US again in a few days but this time on United Airlines, their travel-ready system on their app already says I've completed the entry form requirements without me actually doing anything.

Is this because the form I last filled out is still valid and is linked to my passport? Or should I ignore the United Airlines app and fill in the form again? If so, is there an online form I can use again or am I required to have a physical copy.