Began having dropouts on Wi-Fi with my Hub 3 a year back that became more regular but Virgin couldn't identify any issue, however they sent engineer to replace it so no complaints there. Engineer actually had a Hub 4 & was happy to swap for that but he said he still uses the Hub 3 because the 4 is not as good & has issues of it's own so I stuck with a replacement Hub 3.
Parents are on 250mb & got Hub 4 when moved to Virgin from Sky 3 years back not only have they never had a single issue with internet but their Wi-Fi range reaches literally twice distance mine has ever achieved, now I know structure etc plays a role but there's almost no difference in structure or location plus my hub is actually in an open space dead centre of house so not sure if engineer was simply fobbing me off.
Reason I think this is that shortly before Christmas we again began having occasional dropouts that would normally last only seconds a time over a 30 minute to 1 hour period, no explanation & with only me watching catch up on the 360 box & the lad on his PC gaming. We even disconnected mobiles & Alexa devices so absolutely nothing else accessing web & router correctly configured & secured but still occasional buffering on TV & lag on PC.
Thankfully it hasn't happened since end of Feb' so touch wood it was an issue in street box or elsewhere but if this Hub 3 does start acting the fool again & go the way of the previous I'll definitely be trying to get a Hub 4 because my parents is still functioning perfectly in every way & still has far better wireless range than we have from the Hub 3 even after using coverage checking apps to ensure it's best placed.