Please turn on the WiFi in your phone settings, find the Seestar WiFi connection, and then return to the Seestar App.
Please try switching to 5Ghz or 2.4G, or you can bridge to your home router in station mode, and then directly connect to your home router WiFi to connect to Seestar for control. Here is the link.
Or please check if the VPN on your phone is turned on. If it is turned on, please turn it off and try again.