The following things can cause the image to stand still:

• Your camera cannot get through your firewall properly.  Turn UPnP (Universal Plug and Play) on in your modem.
• You are on a protected Wi-Fi network with your smartphone. Some networks have higher security which can make data streaming difficult, switch your mobile to your mobile internet.
• Your camera does not have enough "freedom" within your network. Look in your modem network environment, find your camera and set the restrictions to Unrestricted.
• Your camera is not connected to your main modem, but to a router or switch. It sometimes happens that routers or switches are incorrectly set within a network. It is then difficult for us to determine what has been set incorrectly. We therefore recommend connecting your camera to your main modem. 
• You do not have enough range with your smartphone. A high camera resolution uses a lot of data, so you need a good range.
• Your data limit on your smartphone has been reached. Some providers "smother " the data usage after your limit is reached, this causes movies etc. to load slowly or not at all. To save data, you can lower the resolution of the camera.