What is the issue?
There is sometimes a misunderstanding of the usage and accessible range of the camera's own WiFi network. The range is limited to 10-15 meters, and is broadcast over the 2.4GHz (DR900 model has 5GHz WiFi) frequency band.
You can only directly connect to the camera when you are in close proximity to it.
Why is this occurring?
The camera's own WiFi network is not a 3/4/5G cellular data connection point. WiFi is simply the "protocol" of connecting your smart device to the BlackVue WiFi enabled camera. The network may be weak or not appear if you are more than 10 meters away, or if there is significant interference between your smart phone/tablet and the BlackVue camera.
What can be done to prevent this?
It is best to think of the BlackVue's WiFi as analogous to Bluetooth. This can help prevent the common misunderstanding of WiFi and what it exactly entails.
If experiencing WiFi connectivity issues between your phone and the camera, ensure you are well within range.