Past two days I have been cleaning here, because today the apartment owner showed up to discuss stuff, and also a technician who changed the modem.
Anyway the apartment isn't gonna be sold for the time being so I won't have to move out for a while. My rent will increase though, but that's better than moving elsewhere (and pay as high or higher rent).
The internet is now 400MBit download and 40Mbit upload. The ISP has been upgrading the connection over time, it started as 100/10, then 150/15, then 200/20, and now 400/40. This time I have to pay a little bit more though, I used to pay 31€ per month for it, now I have to pay 35€ per month.