Central & Northern Europe lower ground images resolution?

Hello, I'm new to FS4, not to Aerofly though, as I already used FS2 in the past. I've installed both DLCs for the European continent on Steam, but it seems like some regions have lower resolution than others (Central Europe, Balkans, Canary Islands, Baltic states and majority of Scandinavia). I've been wondering if that's normal and there's nothing to worry about, or has Steam messed something up and is there any way to fix it? Thanks in advance, cheers