Resetting FTTC profile

Very strange situation - FTTC that has run for over a year fine at 4000 down 1100 up - long line so about the max available - phone lines in area were hit by by lightening & once repaired (inc new mastersocket) we lost Caller Line ID !! - Openreach apparently told Vodafone they eventually found a fault at exchange, and now on fixing that, we have the same synch speeds reported as available (just over 4000 and 1100 down/up) but no matter rebooting or using the test socket & microfilter the uploan speed has been capped at 800....EXACTLY 800 each and every time it is reset !! (normally you woudl expect on a reboot for it to vary slightly each time)
Any ideas what could be causing that ? - it is like the old style profiles at the perimeter of ISP's networks on ADSL ! Is it an Openreach issue, or Vodafone's network?, or could the new mastersocket (the latest Openreach one) restrict speeds?

The IP profile system on FTTC where used is dynamic rather than the sticky of the old ADSL days.

If your sync is 4000 down and 1100 up then throughput should be around 90 to 95% of that.

Error correction can reduce throughput slighter more sometimes, which may explain the 800 up.

Master sockets cannot restrict speeds - they are just simple RF filters.

Thanks Mr S ! The 800up is the sync speed rather than throughput ! I;d have understood throughput being restricted, but any ideas what could cause a line that had previously sync'd at 1.1 to (after an Openreach repair to the cabinet) suddenly only sync at 800?
Vodafone suggested plugging router into the test socket as that would reset the DLM - never heard of that being the way to do it, the test socket surely just isolates any extensions in the house?
Thanks!

At any point time if a line drops and resyncs you might get a different sync.

800 versus 1100 is a marginal change in terms of VDSL2 at the distances you have, so only takes a small change in the noise environment to see you with a lower upstream sync.

So it may well not be DLM but just a small change in line characteristics

On the Vodafone suggestion, that is not the case.

If the sync is exactly 8000 and the downstream SNRM is above 6dB then the DLM may have capped/banded the line.

ISP's can't reset the DLM but they can request OpenReach do it for them.

Good luck getting Vodafone to do that though.

Yes, I imagine it will be a battle to get Vodafone to do anything based on past experience!
It is the Upstream synch which is always exactly 800 now on rebooting, never more, never less!, although the router reports it is capable of around 1100 (the downstream varies around 3800 but changes at any reboot)
SNR is 8 down & 11 up; Att is 46 down and 21 up
Anyone know what the capping/bandings are eg is there a banding of say 8mb down/800up?, as that would explain the up always being capped at exactly 800 but the down varying .

There are separate banding levels for the upstream and downstream.
0.8Mb is likely 1 of the upstream banding levels.

With an exact 800Kb/s sync and 11dB SNRM it definitely looks banded on the upstream.

You're only losing 0.3Mb/s though. Vodafone CS aren't the best. You might struggle to find anyone who knows what a DLM reset is, getting them to action 1 might be a pain.