If you hear your camera saying "Direct Wi-Fi connection already in use," it means that one device is already connected to your camera's Wi-Fi network, and another device is trying to connect at the same time.

When connecting directly to your camera's Wi-Fi network, only one device can be connected at a time for accessing the camera. Check for any nearby devices that might have automatically connected to your camera's Wi-Fi network and disconnect them from the BlackVue network. This can include smart devices such as smart watches, that can connect to Wi-Fi networks that the main device has connected to. 

It's a good idea to turn off "Auto-Join" or "Auto-Reconnect" on your devices Wi-Fi settings for the BlackVue network to prevent it from automatically connecting to your camera when it's nearby without you realising.