So then it's not about the certificate.
It's about the TLS encryption.
Are you sure you are supposed to use the "Implicit TLS/SSL"? On port 21, "Explicit TLS/SSL" is typically used.
If you still have problems, please post new WinSCP log file and equivalent FileZilla verbose log file (not the GUI message log).
It's about the TLS encryption.
Are you sure you are supposed to use the "Implicit TLS/SSL"? On port 21, "Explicit TLS/SSL" is typically used.
If you still have problems, please post new WinSCP log file and equivalent FileZilla verbose log file (not the GUI message log).