Speed drops on WAN port from 500 to 90
My Archer AX11000 router is behind an Experia router/modem, Lan to Wan.
Since a while I had 200/200 internet speeds with actual 200/260 even. No issues. Always working.
Yesterday I upgraded my internet subscription to 500/500 and there is where the trouble starts.
At first the speedtest is doing 480/500 and after a while it drops to 91/91 and stays there. When I connect a laptop directly to the Experia always 500/500 without trouble.
Tried changing cables, complete factory reset, downgraded firmware, altering different settings like firewall and home protection, changing from auto negotiate to fiull duplex 1000, even put the AX11000 right behind the Fiber box without the Experia.
After a lot of changes I do, for a moment (hour max) it is in the 480/500 range again and I am hoping it did the trick, but it drops again. Somehow the routersoftware or hardware is choking the speed down to 91/91.
This is not a wireless issue, this is the speed going into the AX11000, cables are fine and tried a lot of different speedtests.
Anyone an idea what I might be forgetting in the settings?
Anyone think the hardware is broken? Like ports or anything?