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 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.