Phone dropping internet

[#1]

My Internet kept dropping on me yesterday without using the phone. Bt said line check was fine. PN done a check but I couldn’t use internet last night. so today managed to get on Internet is ok bit slow my gaming is a bit choppy. I have new filter and its plugged into main socket But now every time I make a call it cuts my ADSL out then when i hang up it recovers. It can ring, I only get a connection loss when I answer/make a call... The phone and ADSL have been working absolutely fine since I joined PN till yesterday... They are aware of this situation and said they are monitoring, but was looking for advice on what else I can do… No change in connection when plugged into test socket.  Any advice would be a grate help..
JoJo

[#2]

Well other than testing an alernative router (if you have one available) you've done all the tests necessary. On checking your account I can see that one of our agents is testing the line now so you should expect an update to your fault ticket shortly.
You could check for anything electrical in the nearby area that may be causing interference, as that's a possibility for intermittent sync faults.