PPPoE very slow with Sophos XG Firewall

sorry, unfortunately no solution for me.
I did an update on the FritzBox 7490 to the brand-new firmware 06.50. Then did setup the 1&1 dsl internet connection over FritzBox (without XG Firewall) to see whether the dsl-connection generally is fine. Result: Everything is OK: DSL-Connection with full VDSL-100 power. So there is no generally problem with the FritzBox and behind.
After that i did a factory reset on FritzBox and changed the cable installation back to the config "XG Firewall with FritzBox as DSL-modem".
Set MTU to 1492 and MSS to 1444 on XG Firewall and connected over PPPoE.
And, ahhhhh, still the same problem!: Speed not over 2.5 Mbps.
Other solution tips?

Try looking for your QOS settings, might have been accidentally changed to a lower value.

Ian

i have checked this: QoS settings are ok
still at a snail's pace, 2.5 Mbps.
Even if i disable all scanning settings there is no higher speed.

Hi,
what we have't discussed is your hardware eg cpu, memory, NICs and disk space?

i have:
- Mainboard Gigabyte GA-Q87TN (with 2x LAN on Mainbord -- 1x 1 GBits Intel -- 1x 1 GBits Realtek)
- Intel Core i3-4130T -- 2,90 -- 2 CPU cores
- 8 GB RAM SO-DIMM DDR3 1600 MHz
- 64 GB SSD SanDisk X110, SATA 3

i have:
- Mainboard Gigabyte GA-Q87TN (with 2x LAN on Mainbord -- 1x 1 GBits Intel -- 1x 1 GBits Realtek)
- Intel Core i3-4130T -- 2,90 -- 2 CPU cores
- 8 GB RAM SO-DIMM DDR3 1600 MHz
- 64 GB SSD SanDisk X110, SATA 3

I have had a look at the MB specs and it isn't specific about which intel or realtek chip it uses. One of the intel chips does have a problem with the driver used in the UTM, but I suspect t hat is not an issue with the XG.The XG does seem to run new drivers and not some much backward compatible stuff.
Do you have access to a new dual NIC (Intel, Broadcom) to try out?

Hello, thanks for the support. But i can not replace the NIC. it is an Aquado Slim PC and i can not plug in other NICs. I tried to change the assignment of the Ports. So Port1 and Port2 ist now changed concerning LAN and WAN. But no sign of recovery