I got Fritbox 4040 and connected it to my CVE 30360 via WAN.
Wi-Fi works 2.4 GHz and 5 GHz without problems
But LAN is suddenly limited to about 1 mb download speed, as soon as I switch my laptop to WLAN it loads much faster.
I use the same LAN cable as I used before.
Maybe the cable is damaged, otherwise check the router's settings to see if there's any throttling on the laptop while it is connected to Lan.
You have to plug the frit into the hitron via LAN…
Ideally, you should set up the frit beforehand… Change the IP of the frit to the area of the hitron and switch off DHCP very importantly…
https://at.avm.de/service/supportanfrage/produktauswahl/knowlegdebasesupport/detail/de_fritz-box-4040/3244_FRITZ-Box-als-IP-Client-einrichten/#:~:text=Klicken%20Sie%20in%20der%20Benutzeroberfl%C3%A4che,Option%20%22IP-Client%22.
I also checked again as soon as I plug the cable into the CVE 30360 (is still connected to Fritzbox), it recharges to maximum speed, so the cable seems OK. To be.
