One thing is the "rules," but I am seeing a few minutes in difference. Rest time should be minimum the previous duty time is what I am reading from your question, right?
Are you going to make an issue over that, when 15 hours rest will have you ready for the next flight? "They" overworking you again?
Let me ask something else……. Were you off a week before the flights? All rested up and in the local time zone? Are you then settling into a resort for 3-4 days after getting back to US?
Or are "they" running you ragged?
I would consider the totality rather than 20 minutes difference in your calculations to make a point with "them."
But just a few random thoughts when reading your question.