Hi,
I already tried to reach out to the support by email but I'm posting here in case someone solved this issue.
Since I bought my new DIR-855L, the wired/wireless Internet speed has been very slow. I have fiber (Coextro in Canada) and if I plug my laptop directly to the wall using a gigabit ethernet cable, I can reach 120mbps+; with the same ethernet cable and through the D-Link routeur I can't even reach 1, everything is very laggy. File transfers inside the local network are fast though, over ethernet and wireless.
I tried:
- Updating the firmware to the latest version
- Reverting to Firmware Version: 1.01
- Reset with no customization
- A different electric wall plug
- A voodoo incatation next to it
- Validated that QoS is disabled
- Disabled Wifi to use only Ethernet
Nothing worked... Any ideas welcome

Thanks!