Displacement map bad results

you could technically mask out low coherence areas (described here: Is it the right way to create mask for phase unwrapping?), but this would leave you with the small coastal area.

I’m afraid, there is too much vegetation in your area which causes phase decorrelation. Even if the images were only two days apart, the coherence would probably look the same. Unfortunately, DInSAR has its limits over vegetated areas.