Rule reminder
'Andare + gerundio' expresses a gradual, ongoing process or trend that unfolds over time — NOT a snapshot of right now. Think of it as a time-lapse: 'il problema va peggiorando' = the problem is getting worse and worse (over time). It is more literary/formal than 'stare + gerundio'.
The situation is gradually improving (over the past weeks). Which is correct?