No point in resetting DLM until the fault on your line is fixed.
if your internet conenction is dropping every couple of days even with different router then you have a problem either with your conenction inside or outside your home are you using test socket with filter to eliminate internal wiring and faceplate as being a problem? even if you currently have a filtered master socket
as @licquorice said you need to get stable conenction before a DLM reset will be any good for more than a few days maybe you need to get engineer visit
I obviously misunderstood your initial post
'had a few resets of router line won't Settle again as ever 2 day the bt smart hub resets it self I have 4 other bt routers that do the same '
look forward to update that DLM reset
It will be interesting to hear how you get on if indeed you get a DLM reset. The problem causing the hub resets needs sorted first.
Please keep us updated.
So why are you still using one?
Edit: You are either very unlucky with the hubs or something is causing the resets and I know which I think it is.