@ABraun Thank you fir the comment. In the processing graph I use the topo phase removal is included.
Actually the epicenter should be on the west south side according to the European-Mediterranean Seismological Centre . The red area correspond to agricultural areas so low coherence is expected.
Also I’d be interested if sea mask can applied without affecting the unwrapping.
BTW Similar results are reported by NOA Greece - http://beyond-eocenter.eu/geohub/ionian-sea-2018-10-25-225451/?fbclid=IwAR0oIz1pg3HmwRZwN7azHyoxwzprKHWgOrAD1JpsrQE8XG8NcFRuH3gD-4E
One more interesting fact is that between the acquisition of the images I used for processing there are at least two events with Mw above 5.