A lot of service providers do this because they do not want you to host static services from your "dynamic" home IP, as they are selling "business" lines with dedicated static IPs. Or at least they used to do this for that reason. By now it's just some thing a lot of ISP do. I have seen other possible explanations like ISP claiming this is a "security" feature because attackers cannot have permanent access without always learning the new IP, which is supposedly somehow hard. This is pretty bull tho. If attackers have access to your system they could just run software signalling them back any IP changes. And even nmapping the entire IP space of an ISP to find a service you were hitting again is very feasible.
Anyway, if the ISP does this, then you have to reconnect once every day (or sometimes every two days), and if you don't do so manually they will just cut your connection on their side and make you reconnect.
My (German) ISP does that too, the one I had before did it, the one before did it as well.