Based on our past experience, this connection issue could be due to your NAS and PC being on different network segments.
Could you please provide screenshots of your computer’s IP and NAS’s IP? (If you have privacy concerns, feel free to send them to me via private message.)
Also, we suggest you ensure both your devices are on the same network segment. For instance, try connecting both devices directly with an Ethernet cable to the same router, and then use Qfinder to see if that helps.