IP address compromised

[#1]

My broadband connection had been dropping for the last few days.  Changing modem/router and cable connections did not help.  This morning  I got a call from BT saying that my IP address had been compromised and it would be changed.  Since the call my connection has stabilised. What's this all about?  Anyone know?

[#2]

Is your phone service with BT then? Suspect it was a scam call where dishonest Indian call centres
ring you saying they're from Openreach & your broadband is compromised/ you'll be cut off bla bla.
Just hang up, never respond or give them remote access.
I respond by blowing my trusty Acme Thunderer whistle down the line to give them more ear ache than they gave me.

[#3]

I see. A variant of the Microsoft scam call.  He did not stay long enough on the phone to try to gain control of my computer.  That's what made me think he was a BT engineer in a hurry.