Negative review for performance

I have been working as a full-stack developer past 2 years and now in onsite since 3 months. Based on my performance they were happy and called me onsite since our project is going live in 3-4 months.

I have been completing whatever tasks have been given to me and asking for more tasks once I complete them. I did work on weekends and completed the work irrespective of the tight deadlines. Now the manager communicates to me via a senior person that my performance is going negative out of a sudden and I didn't meet their expectations and need to work more proactively. I repeatedly asked him based on what parameters they came to this conclusion, he simply said take this as a positive feedback and work towards it, without telling the actual reason for this review.

What should I do : take a release while the live implementation because this might affect my career prospects.