Linux – Have to restart NetworkManager to get wifi autoconnect

I'm running Antergos (Arch) with KDE Plasma, all works but from last couple of days I have a network problem: wifi doesn't autoconnect.

I use NetworkManager.

Well, in fact, it autoconnects, but only after 5 minutes starting from boot! (5 minutes more or less).

Forcing the reload with

systemctl restart NetworkManager

It autoconnects.

Using journalctl, the (partial) output is:

dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0095] policy: auto-activating connection 'Wifi_Casa'
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0106] device (wlp2s0): Activation: starting connection 'Wifi_Casa' (8a912e7f-0989-4d91-b9ae-b42e85eb37c6)
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0109] device (wlp2s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0110] manager: NetworkManager state is now CONNECTING
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0123] device (wlp2s0): set-hw-addr: reset MAC address to 10:02:B5:05:F0:EB (preserve)
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0174] device (wlp2s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0176] device (wlp2s0): Activation: (wifi) access point 'Wifi_Casa' has security, but secrets are required.
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0176] device (wlp2s0): state change: config -> need-auth (reason 'none', sys-iface-state: 'managed')
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <warn>  [1513624133.0185] device (wlp2s0): No agents were available for this request.
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0186] device (wlp2s0): state change: need-auth -> failed (reason 'no-secrets', sys-iface-state: 'managed')
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0187] manager: NetworkManager state is now DISCONNECTED
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <warn>  [1513624133.0189] device (wlp2s0): Activation: failed for connection 'Wifi_Casa'
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0194] device (wlp2s0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0207] device (wlp2s0): set-hw-addr: set MAC address to 52:7C:11:E8:AA:36 (scanning)
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0506] device (wlp2s0): supplicant interface state: ready -> disconnected
dic 18 20:08:53 marco-E7450 NetworkManager[640]: <info>  [1513624133.0559] device (wlp2s0): supplicant interface state: disconnected -> inactive

Strange things are:

1. After 5 minutes (5 o 6 connection attempts, with the same output message) it works automatically.
2. If i reload NetworkManager, it immediately works.

What can i do? (I've tried to reinstall NetworkManager, nm-applet and all thing related)

Thanks in advance