To make stable connection and more powerful performance, turn off power management for wifi is one of choices.

edit /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf

wifi.powersave = 3

Change the 3 to a 2 and reboot. Then run iwconfig and if it worked you should see Power Management:off

$ iwconfig
lo        no wireless extensions.

wlp6s0    IEEE 802.11abgn  ESSID:"UoA-Device"  
          Mode:Managed  Frequency:5.805 GHz  Access Point: B8:38:61:4F:18:9C   
          Bit Rate=360 Mb/s   Tx-Power=17 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=47/70  Signal level=-63 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:1   Missed beacon:0

enp5s0    no wireless extensions.

enp0s31f6 no wireless extensions