Security concerns aside, you'd need to chase the port forward through all three, so Inet'TCP21>ISP>TP-Link>UXG>ftpserver. As you say, not ideal. I have a similar setup with multiple NAT hops - they're frowned upon, but that's a discussion for elsewhere.
Alternative is to run a reverse proxy, but it too would need to traverse your network somehow.
Security concerns aside, you'd need to chase the port forward through all three, so Inet'TCP21>ISP>TP-Link>UXG>ftpserver. As you say, not ideal. I have a similar setup with multiple NAT hops - they're frowned upon, but that's a discussion for elsewhere.
Alternative is to run a reverse proxy, but it too would need to traverse your network somehow.