Cheers for the heads up I didn't know that! Why would Openreach do that? So annoying!
Will look into getting a Broadcom based modem I think
Blame Asus. They are the ones who picked the MediaTek chipset.
It's a horrible chipset that doesn't adhere to many of the standards and was obviously causing issues with G.INP active.
OpenReach have a list of approved modems and the Asus (or any Asus) isn't on the list.
Your ISP should also take some of the blame for issuing them.
If a poorly designed modem is causing issues for everyone else on a cabinet it's right that OpenReach take action.
There was an issue a while ago where a specific modem was breaking the entire DLM on a cabinet. Although the manufacturer name wasn't released there are many of us who strongly suspect this was Asus devices.
If disabling G.INP on those devices fixed the problem then that's a better solution than OpenReach disabling your connection or forcing you to change equipment.