Hey ^^
Wifi is buggy in the official firmware ^^;
I think I have to write more documentation on my firmware
Get the firmware :
https://github.com/psolyca/Yi_4k_ROOTFS/releases/tag/v1.10.51
Put it on a SDCard and rename it "firmware.bin"
Reboot the Yi, follow the update process
Yi4k rebooted, got to menu and check version, 1.10.51.