ADSL connection speed varies enormously many times a day

[#1]

I have a Plusnet-supplied Thomson TG 585 v8.
Bert

[#2]

Perhaps someone familiar with that router could say if it has an idle timeout setting.
What version of the firmware do you have on that? I'm wondering if you need an update.

[#3]

I just checked, and I have firmware 8.2.7.8 which I believe is the latest version.  I can't see any information about an idle timeout setting.  And actually, thinking about it, the connection has been idle for lengthy periods in the past without dropping the line, so I rather doubt if that's the problem.
Bert

[#4]

Yes, 8.2.7.8 is the latest TG585v8 software.
There might be an idle timeout setting somewhere in the CLI but I'm fairly sure it doesn't appear on the GUI. My settings are default and I don't get disconnections.

[#5]

This problem seems to be getting worse, with disconnections/extreme speed drops happening more and more frequently.
I was thinking that I could live with it until I change to fibre (in two weeks time) but I was wrong.  So I'll take the advice offered here and try a different router.
Bert

[#6]

If that doesn't fix the issue then raise a fault for us to look at https://faults.plus.net

[#7]

I'll do that, thanks.
Bert