Why is Bill stuck in pending status?

Hi Support community. I'm currently facing a problem that can hopefully be resolved urgently. Some bills assigned to specific approvers were approved. On their end, the system notes shows that it was approved. However in my administrator role, I cannot see that it was approved in the system notes and its status is pending. The approvers also lost the approve button.

I have tried setting to debug level the SAS- Recreate Mirror approval script and entering the internal ID of affected bills, however this did not solve the problem. I have also confirmed that there has been no recent changes in the vendor form or in the bill form. I have also eliminated the currency mismatch as the currencies in the transaction are also matched with the currencies in the vendor record.