I assume with a dedicated host plan you have checked most everything needed.
But in my case I find I have intermittent connection issues caused by my isp which makes timeout errors. Which is really hard to nail down with my local provider.
Because they send the contractor first,Then they send a tech, then they issue it to a distribution tech which checks the hubs amplifiers and transmission lines down the street.
All of this takes several days or weeks sometimes. Then when they get here all is fine.
So possibly a hop from your users is the culprit.
