I cannot access my FTP server using FileZilla or any other FTP client.
When I use Bitdefender VPN, I can access it without issues, but without a VPN, FileZilla will not access the server.
I have tried troubleshooting with the server administrator, and they have confirmed that there are no blocks on my IP address or from their side. Also, they found it unlikely that Spectrum (my IPS) would block access to my ports.
Their best suggestion was to contact Bitdefender and ask how to resolve the issue with FileZilla being blocked.