I can't guess what all is on your network but the HZGTC LTD company you mention makes a lot of things including a WiFi module you might find in solar panel management, IoT or any number of WiFi enabled devices.
This does not mean there is a security issue yet. It only means you may learn more about your WiFi devices.
Today I set up a ASUS RT-AC58U router, and added NordVPN to the Modem using OPENVPN (in router settings). I downloaded the app provided by ASUS to monitor my network traffic. I was shocked to see the following company „Hui Zhou Gaoshengda Technology“ as part of my network. I have no idea how did they join it, and what does it mean. I blacklisted the device from my device connection.
Wondering if any of you had similar experience with ASUS & NordVPN. Is it a security flaw? Any suggestion would be really helpful.