@SeoulGal 

You prolly dont want to hear this, but here goes anyway.

I have one device (thermostat controlling device) that doesnt want to connect to the Deco's.

Tried everything but to no avail.  I did some research and it turns out that this device contains a wifi chip that was soldered in by Edison himself or something. Very old and for some reason not compatible. If you ask me, just another shortcoming of the Deco's, but since it is only 1 device ( of the +30 I have connected) I'm willing to let this bug slide.

Anyway, the only solution for me was to either replace the thermostat device, or keep an old wifi accepoint around just for this device. 

On the other hand, I dont have a Victure camera, but from your wifi config description it sounds a lot like a run of the mill chinese firmware that is powering your camera. And I do have one of those.  I couldn't connect that one either. Untill, and I know it sounds weird, unitill I removed it's SD card. Then it would connect fine. Putting the card back in it and sure enough, it failed to connect again. So this proves that the error 'password not correct' which mine also said, was not it's true problem.

In your case you might want to check there is not something blocking it's way to the chinese server your authentication against. Maybe som firewall settings in the Deco? Maye change the DNS server?

@TP-Link_Deco Thanks, I already tried all of that but no luck yet.