That's just how the game map works. Stardew will show which area you are in (in this case you're in Cindersap Forest), but never an exact location. The main feature of the game map is that you can tap on a building to see it's hours.
Huh, I could have sworn it showed me more precisely in other parts of the map. After testing again, it looks like Pelican Town just has more “areas”. This is what I was probably seeing. Thanks for the reply!