CM1200 slows down after 24-48 hours of uptime when using link aggregation

Here is the issue and fix. I have the same moden and the Nighthawk AX8 router. My modem was giving me speeds at the average 900's mb/sec and every 12hrs, the speeds would drop to 12mb/sec. I would the reset the modem and the speeds would increase to my 900's mb/sec speeds. I then tried aggregation and it worked for a couple of days my speeds stayed at 900's mb/sec without issue then it began to drop back to 12mb/sec. With the AX8, you can test speeds directly from the router/modem and then I would test the speeds on my Nvidia Shield and they would match. First, Comcast is pissed that you are using their modem for $13/month. Secondly, you will actually have to contact a technical support supervisor. So I decided to call XFINITY (Comcast) and raise hell. They first began to speak me me as I am an idiot and dont know anything. You will have to reiterate that the Nighthawk CM1200 is compatible to their network and is also listed on their website. They ask you speedtest questions and things. Then they will talk down to you. Log into your modem and tell them you can see the frequency and they are not what they should be. Now asked them to bump up your speeds and then lock in the modem. They will argue a bit but they have to do it. Once modem is locked in I. And speeds are bumped, you will not have to restart the modem every 12-24hrs. They are trying to force you to use their modem which then dictates the speeds your devices are allowed to get.

P.S. I have a Galaxy S10 5g, and need to know how to configure the wifi settings to get almost gigabit speeds on 5Ghz. I can only get 325-450mb/sec, which I know the phone is capable of faster speeds