Question internet speed drops from 200mb to 100mb in an hour

[R3ayed]

hi,
as it says in the title i have a problem with my internet speed
it used to be fine until about a week ago when it started to drop down after an hour or so of restarting the router/modem.
on WIFI 5g tho i get the full speed,
i tested it with a 1Gb device and a cat6a cable and it always drops after a while below a 100

 

[jsmithepa]

1. Turn off any power saving mode.
2. Aware of sufficient ventilation to base station.