My dxp6800 pro can’t be discovered/found on the network by ugreen nas apps.

Hi all, I just got the dxp6800 pro and tried to set it up. I downloaded ugreen NAS apps on the iPhone and also on my Mac. I have 3 routers at home and I tried all of them. I connected the NAS to all routers one by one and each time it can’t be discovered/found by the apps. I know it is connected to the router because when I login to routers I can see it there and has ip assigned to it. The light on the network port also indicating it is working. Using the QR code to set it up also didn’t work. The iPhone and Mac are on the same access point as the NAS when doing this setup. I know the NAS is connected to the router and I can even connect to it using the ip (http://192.168.xxx.yyy:9999 and able to see the setting there. I updated the NAS too with the latest software.

My only problem is I can’t see the NAS from my iPhone or Mac.

Does anyone have issue like this or know how to fix it? Thanks all.