Motorola MB8600 Drops internet, slow speed.

I have an issue with Motorola MB 8600

Modem intermittently drops speed, loses internet, crashes network.

I checked all cabling, rebooted numerous times, updated router firmware (archer tp-link) and still had issue.

If you reboot modem, it will come online and give up to @ 50 MBPS speed, no faster. Then it degrades almost every time you run a test until it goes below 1 MBPS and internet is unusable.

It randomly does this many times a day.

The blue bonding lights on the modem flash many times when you go look at it.

Tried to use xfinity diagnostics and/or reactivate modem, but X app could not find modem even after ten minutes.

Could not get to modem log page using modem IP.

Then, after a huge time waste and frustration, I finally re-installed my old modem (arris surfboard docsis 3.0)

Used x app to re-activate the old modem.

X app saw it and activated it in like one minute.

Now, speeds are at @ 95 MBPS and consistent.

Does not crash

I can use the IP and see the log file.

What is the deal here?

Is Motorola MB8600 just not really compatible or something?

Is mine defective?

I see many cases of trouble online with this modem and Xfinity.

It was ridiculous the amount of trouble I had on initial install (they had to send a tech to my house) and nothing but trouble since.

For now, I will keep Arris Surfboard docsis 3.0, but it was Xfinity themselves who told me I needed new modem to get top speeds!

I used their own list of compatible modems to replace the arris and it was NOT working.