Sync speed slowly dropping

[GordonUK]

My sync speed is slowly dropping as below;

79.9 Mbps First activated 3 years ago

74.5 Mbps about 6 months ago

70.6 Mbps about 3 months ago

64.5 Mbps now

I have contacted Vodafone by chat twice and by phone twice but no one is interested because I am still above my guaranteed limit which is 63 Mbps. I was given the excuse that the drop is because of the pandemic and everyone is working from home. 
I live close to my cabinet and have had BT and Plusnet in the past and speeds have never been so low. My equipment setup has not changed and I am still in contract with Vodafone until December. I have reset my router and completed a power cycle as requested to no avail. I have asked on each occasion to speak to second line support but have been refused. 
Any advice would be greatly appreciated. 
Thanks. 🙏 

[Jayach]

The pandemic will not affect sync speeds, I don't know how they can come up with such rubbish.

Have you tried with it in the test socket, preferably with a different filter if you use one. Filters can become faulty.

What are your other stats such as SNR?

[GordonUK]

Thank you Jayach.

I have an Openreach MK5 Faceplate, so don't have any filters but will borrow one and try the test socket.

I have just been told that the reason my sync rate is dropping is because I have more than 15 devices connected to the router? Now I don not know very much about broadband but even I know that is not correct.

Current Rate	64484 kbps	20000 kbps
Maximum Rate	79423 kbps	23478 kbps
Signal-to-Noise Ratio	6.6 dB	6.3 dB
Attenuation	DS1 5.3 dB, DS2 11.4 dB, DS3 18.9 dB	US0 0.1 dB, US1 8.4 dB, US2 13.0 dB
Power	-6.1 dBm	-6.2 dBm

[Jayach]

Interesting, your line appears to be slightly longer than mine. I'm no longer using the Vodafone router but my last stats were

Current Rate	78687 kbps	20000 kbps
Maximum Rate	80383 kbps	28819 kbps
Signal-to-Noise Ratio	6.1 dB	11.5 dB
Attenuation	DS1 8.8 dB, DS2 21.2 dB, DS3 33.0 dB	US0 1.9 dB, US1 14.6 dB, US2 23.4 dB
Power	12.7 dBm	3.3 dBm

so you do seem to be loosing quite a bit off your maximum. Lets see in a another filter makes a difference as the filter in the face plate could be faulty.

I can understand Vodafone's reluctance to call out Openreach as you still have an acceptable sync, it's just annoying when you know it could be better.

[GordonUK]

Thank you and you are absolutely right, it is perfectly usable, just annoying!

I am borrowing a plug in filter tomorrow, so hope it works. 

[GordonUK]

Just remembered I had on old router box in the garage and it had a brand new filter in it.

Tried connecting directly to the test socket but Stats are almost identical to it being through the faceplate. So at least I know the faceplate isn't faulty.

[Jayach]

If your old router is VDSL you could try connecting it up. It won't authenticate to Vodafone but it should sync. That would eliminate/prove the Vodaphone router. Only problem is too much disconnecting/reconnecting could trigger DLM.

[gipjon]

I would say crosstalk in the fibre cabinet , As more and more user get connected in your cabinet the crosstalk goes up ,this normal takes a few years like you said in your first post , I would not keep unplugging the router and trying difference filters, as you may trigger the D.L.M into thinking you have a line fault and this will slow you down by quite a bit and turn interleave on more etc . also what interleave is your router reporting 

short story there is nothing you can do about it apart from work out if your S.N.R goes up in the middle of the night. if its gets above 7 or when the S.N.R is at its highest in the middle of the night, disconnect and reconnect the router this may give you more speed but i would wait a month before you try this 

best advise i can give you is forget about it and go to the pub and get wasted