The latest firmware is 22.214.171.124. Should not make a difference in your case but there were some stability issue with 126.96.36.199.
Can you reach the VNC server locally using port 5901?
Is the RV220W the Default Gateway of the server?
Have you tried forwarding any other service to any other device?
If you enable Remote Management on port 443 and scan with yougetsignal, does it show "Open"? If yes, try using port 5901 for Remote Management and do the same test. (You may have to disable the Access Rule for 5901)
If the ports are showing "open" for remote management, then there are no issues with the ISP and the configuration is incorrect. In that case I recommend that you call support for configuration assistance or post screenshots here so we can figure out what is wrong.