Crosstalk effects?

[#1]

Hi,
Since I have been connected to fibre several weeks ago my attainable rate and SNR have been slowly declining which I have always attributed to crosstalk.
However since Saturday when I had G.INP enabled the attainable and SNR have declined quite quickly, this could obviously be a coincidence but thought I'd post here for some thoughts.
My SNR has dropped from 10db to 6db since the weekend and my attainable has dropped from 98000 kbit/s to 81000 kbit/s.
Please see the attached screenshots.
Any thoughts?

[#2]

The attainable rate is nothing more than an estimate by the modem that depends upon its own algorithm and the current sync speed and current SNRM. Different modems could give different values, so I wouldn't take too much notice of them. The SNRM is (obviously) the thing to keep and eye on (along with sync speed).
No obvious explanation for what you are seeing, but just a couple of thoughts - I assume it has the latest firmware and 2nd, is it well ventilated - this isn't some sort of thermal effect possibly?

[#3]

Thanks for the reply.
Yes the latest firmware 6.20 for the Fritzbox 3390 and it is well ventilated.
Tempted to restart the router to see what happens.

[#4]

I'd be more tempted to watch a while, if your SNRM goes below 6, you might end up with the sync speed dropping, I can't judge that with your line attenuation, you might be able to better than I could. If you choose to do so, apart from the SNRM consideration, you'll probably have no issues with a single reboot, I don't know what your uptime is, but the errors seem pretty low, but at other times I'd be inclined to say the safest option is usually to power it off for a minimum of 30 minutes.

[#5]

Had to try a restart 
Looks a lot better. Maybe it just needed a full restart after G.INP was enabled.
I'll keep an eye on it.

[#6]

I must admit, I might have been tempted as well, but telling someone else to do it on their connection is another matter
Yes, that looks pretty good, maybe that's what it did need. Hope it stays stable now.

[#7]

Thanks for your replies, really appreciate it.