The wildcard certificate is successfully installed, but Filezilla still shows warning when using to connect, which is using TLS.
Please be aware that it is expected behavior of FileZilla. FileZilla doesn't know any certificates by default. It does not use the OS certificate store at all.
FileZilla will always ask about trust certificates. Once the user selects to perpetually trust this certificate (s)he won't be asked again for this one.
Note that invalid (e.g. expired) certificates cannot be trusted permanently, the option is disabled in this case.