Test Items :
1. Wi-Fi dongle is not loose :
Make sure the Wi-Fi dongle at the back of the machine is not loose, and the antenna connector has been tightened.
2. Shorten the distance between the machine and the hotspot :
Shorten the distance between the machine and the wireless network source (router or hotspot), or try to use a wired connection.
If the above items do not solve the problem of slow camera preview speed, please refer to "Camera Preview Timeout or Failed to Connect" or contact your reseller.