Re: Please check these stats. Getting terrible lag
The downstream post-RS errors indicate a noise ingress problem across all channels, but particularly around 219 and 227 MHz. I'd hazard a guess that the particular noise is probably due to DAB broadcasts on VHF band III, in particular sub-bands 11B and 12C, although internal signal reflections due to cable damage are a possibility. Others may have better knowledge of the specific sources of noise in VHF Band III rather than my assumption of DAB, but regardless of source, there's a noise issue on those frequencies.
Whether noise ingress or reflections, they both suggest either a damaged coax cable (or an unsuitable self-supplied one, eg to move the hub), a poorly made connector, or an uncapped coax port, any of which could be on the same segment you're connected to. When I say "same segment as you", it means that the source of the noise could be on a neighbour's connection, not necessarily yours, but in that case it's VM's problem to trace and resolve it.
What you can do about this is limited, but includes the following:
1) Check that all VM related coaxial cables are as supplied by the company, have the connectors properly made and tightened. So undo each connector, give it a wipe on a tee shirt, damp rag, kitchen paper, reconnect, and do up any securing nuts finger tight.
2) If you're able and willing, do the same in any brown plastic wall box on the outside of the property. These joints tend to be tighter, and you'd probably need a small spanner or similar to undo and redo them, along with a screwdriver to get into the box. If you're not confident to do this, don't attempt it.
3) If there's any unused VM coax ports (eg from a now unused TV box, or previous hub location) they need any ports to have proper caps fitted. Those are usually F-type male terminator caps that you can get for a few quid in any hardware shop.
4) Check for damage on the coax cable such as crushing, kinking, staples or cable clips that have gone through it.
When you've made those checks, turn the hub off and then on again - that will clear the error counters, so you'll soon see if the post-RS counts start rising (pre-RS can usually be ignored). If after this the problems persist and post-RS counts are rising, then it's VM's problem to resolve, and you can ignore any daft advice about "wifi devices too close to the hub", that has no bearing whatsoever on the problems the hub's status data is indicating.