We can accept being loved after the correction. That is how everything else works.
Paul puts the love before it. While we were still sinners. Not after the improvement, not on the strength of a trajectory, not because God could see where this was heading.
That word still is doing all the work, and it is the word we edit out. Most people carry a version where God waited for a sign of promise. It is a more familiar arrangement and it is not what is written.
Which has a practical consequence. If the love arrived before any of the change, then failing again cannot undo it. You were not accepted on the basis of a run of good form, so the bad week does not repeal the terms.
God proves His love in this. Proves. Not offers, not expresses. It is presented as evidence, already submitted, no longer under review.