Based on the fact that the speeds are symmetric, I am going to assume it's fiber then. I found this page which describe how the ISP works. It's a non-profit collective of housing authorities(HOA) owned by the user. This makes the situation much more complicated because there is no default install or setup. It's different for each HOA. From
this page;
"Parknet is a user-owned organization that provides telephony, internet and TV to Parknets members. Membership is open to housing associations, associations broadband, antenna, colleges and the like.
The member must pay the costs associated with the connection of the member to Parknets network. Due Parknets attractive prices serve member associations normally costs of connection home quickly."
I was digging around for a support page, but can't find one. I did find one mention that the default router they give out is the DIR-850L so that tells us we are in the right ballpark at least. I also found mention that they charge extra for both public IP and static IPs, which would leave the default to be private DHCP IPs.
Did you pay someone before to use a static IP?