Cannot register in the personal account of the pension fund

Good day! I have a problem: I cannot register in the personal account of the Pension Fund of Ukraine. When trying to log in using PrivatBank's QES or through Diia, an error appears stating that 'you have not been identified, you need to contact the Pension Fund.' I contacted the Pension Fund branch, but the employees also could not help, as the system gives the same information, and they do not know the reason. Their system does not find me. Please tell me what to do in this situation and where I can turn? I receive state social assistance for group 2 disability. Previously, I was registered with the social service, but since July 1, the Pension Fund provides social assistance payments. However, I cannot register in my personal account due to this error.