@Wassbergh Try switching out the flat ethernet cable to a stock 5e (or higher) of your own. Since I switched cable I have had no more issues, independent of other settings.

@Yahyoh Did you try turning off all QoS and setting limit to 1024? I only have the one, so I can't replicate your problem but I did all that and switched cable at the same time so I can't actually be...

@Yahyoh I actually found the answer, kinda hidden, above: Have found that some cables provided with gear from the provider or other router manufacturers may say they are rated for 5e/6 but in fact...

@TWPS I'm having the exact same issue since my broadband got upgraded to 1000/1000mbit. It works for a while if I switch around the cables, but after a bit the Deco reports to the modem that the...