I'm also from sweden.
I have telia open fiber with telia as isp.
I have connected the R1 directly to my incoming switch, then the vacxtream behind the R1, just for Wifi.
Switch(Lan1 red)>Wan R1>Lan1 R1>Lan1 vacxtreme.
I have disabled Dhcp and nat on vacxtreme.
I've heard that it could be a dhcp lease time about 20 min for telia.(not sure)
Maybe wait a while after you plugged in the R1 and restart.
You shouldn't need the vacxtreme, if you don't want to use it.