Had 100mbps local ISP internet, 10 days ago changed to Starlink, my old router was 100mbps, so I bought new ones two Deco s7.

Starlink router as derived mode and conected to a Principal s7 (mode router) via cat 7 cable, from one port there is 15 meters cable (Cat5e) an another s7 (secondary)  and from it a gaming PC, another 6mts cable (cat5e) comes from principal deco to another gaming PC.

Wifi works fine i'm having 250-270mbps, if I use an old usb wifi adapter in my pc I have 75mbps (device has like 12 years), If I use my phone via usb to the PC I get 250mbps (all this with both deco).

Now the fun part! both PC conected by ethernet are getting 10mbps, tried everything, from QoS, change cables, switch decos, I factory reset them, I upgraded the firmware, nothing seems to work, even tried to force PC network card to 1gbps and speed still 10mbps, yesterday I disconected all decos and put the old router into the starlink and the pc's at the router's fast ethernet ports and bingo, PC's had 97mbps (router ports are capped at 100mbps).

My only conclusion is return this routers, and buy someting better, any suggestion?