Anomaly with Job Success Score?

Question

Upwork

I have a very strange situation, but as far as I understand this is not a very rare case.
I worked on upwork for about 2 months during this time I took 6 projects, closed three of them with feedback 5.0 (Clients in correspondence confirmed that they were completely satisfied with the work, we I sort of rule out a possible negative private review..
I have three projects in progress but today I got a Job Success Score of 63%, Does anyone have any idea why this could happen?

Answer 1

As mentioned above, one of the customers left a bad private review. I recently also started, there were 4 projects, all except one client (that's for sure) put 10/10 and one 1/10. As a result, 75% JSS. And then the only way out is to try to take on new projects and close them perfectly

Answer 2

Bad private review. Intentionally or unintentionally supplied by the customer.

Answer 3

apparently one in three customers gave a bad review