At times, the Canon Camera Connect application for iOS may behave incorrectly when attempting to connect an iOS device to a camera via Wi-Fi . Deleting the app's saved state in the background can oftentimes correct this. This does not harm the app or the device and simply causes the app to launch with a default "state", which can eliminate many issues that prevent the app from connecting to the camera and performing correctly.
1. Camera's Wi-Fi is set to [Enable] If [Built-in wireless settings]'s [Wi-Fi/NFC] is set to [Enable] under [ Connecting the Camera to a Computer using a USB Cable (EOS 5D Mark IV).
Press the [MENU] button on the camera to open the menu, switch tabs, and select [Wireless communication settings]. Selecting the Wi-Fi function settings menu Select [Image Sync], and set either [Still images only] or [Still images + video].
Countermeasure For EOS cameras with Wi-Fi functionality, the camera can be accessed by the EOS Utility software application via a Wi-Fi connection. For details, please review the user manual.