To identify the cause of a slower WiFi connection than a wired connection, it is best to check the following:

1. Location of the wireless router: Make sure that the router is located in a place that is away from interference from other wireless devices, including phones, microwaves and baby monitors.
2. Distance from the WiFi router: The farther away your device is from the router, the slower the connection will be, so try to minimize the distance as much as possible.
3. Network Security: Check the type of security the WiFi router is using. The newer WPA2 security is more secure than older WEP security, and it can also be faster.
4. WiFi Channel: Check the WiFi channel the router is using. If there are a lot of devices on the same channel, it can cause interference and slow down the connection.
5. Device Settings: Ensure that the device is optimized for maximum WiFi performance.