It could be indeed a max amount of devices....but then again... I had a problem last week...and there was some noise on my line so there was placed a filter ...blocking me from internet so that I didn't destabilize the whole street. They replaced the router and removed a little piece of wire. I think that there is still something causing a problem.
Will give them a call to check if they have a limit on devices placed on my line.
Thanks!
If they do indeed have a limit, one way around it is to put a router between your devices and the ISP's router so all your devices will appear as one device to the ISP's router.