Comment # 22 on bug 915160 from Pawel Wieczorkiewicz

(In reply to Marius Tomaschewski from comment #19)
> Pawel,
> it seems to be some HW/chipset related thing -- can you take a look?

Yes, this is a typical iwlwifi driver problem of 2015. I had one myself and
experienced a lot of similar issues.

The association, authentication and connection works fine. There is no problem
with NM nor dhcp client. Simply the first data (which is dhcp discovery here)
transferred over the link makes the driver wrongly realize something is wrong
(low signal, bad channel or something like that) and that triggers the reason=3
local disconnection.

This is what helped me back then:
1) sudo iwconfig wlan0 power off
2) add wd_disable=0 option to your iwlwifi line in your
/etc/modprobe.d/50-iwlwifi.conf (or similar).

But hopefully these problems are history now with more recent drivers for Intel
Centrino and alike chipsets. So definitely upgrade and give them a try first.