Getting error while connecting FTP via Filezilla

Could be CSF Firewall has blocked your other IP. Similar to Sysadmin - Locked myself out due to CSF? How long is the IP blocked? maybe ?

more info might be helpful

1. What version of Centmin Mod ? .08 stable or .09 beta ? If .09 beta when was it installed and when was last time you updated the code ?
2. What's your VPS/Server hardware specifications ? Xen/KVM/OpenVZ ? cpu type ? memory available ? disk space ? OS and version ? i.e. CentOS 6.10 or 7.8 ?
3. Who's your web host ?
4. Your ISP ip address static/dynamic ?
5. What were you doing connection wise to your server leading up to the blockage ?
6. If you're on dynamic ip, you may need additional steps CSF Firewall as per Getting Started Guide step 4
7. If you can, check if you ips are blocked using csf -g grep command.
   
   Code:

   csf -g YOURIPADDRESS

   commands you can see for csf via
   
   Code:

   csf -h

   whitelist your ISP range of ips if you know the range
   
   Code:

   csf -a IPADDRESSORRANGE

   remove temp and permanent blocks from csf
   
   Code:

   csf -tr IPADDRESS
   csf -dr IPADDRESS

   also check CSF /var/log/lfd.log for clues. Don't post the output of this command due to sensitive info
   
   Code:

   tail -50 /var/log/lfd.log

   another log is /var/log/messages you can grep it for your ips. Don't post the output of this command due to sensitive info
   
   Code:

   grep IPADDRESS /var/log/messages

   and your /var/log/secure. Don't post the output of this command due to sensitive info
   
   Code:

   tail -20 /var/log/secure

Do you have a VPN connection you can use ? Try using that to FTP into your server to see if it's just your specific IP that is an issue. If you have VPN like private one with dedicated IP, you can also whitelist that VPN IP in CSF Firewall. That's what i usually do so have multiple avenues to connect to server via SSH.