If you were in a second career and were coming from being a teacher to engineering, then that is something that wouldn’t spark a second look.
These large engineering firms employ former military vets, Stay-at-home Moms/Dads, retired teachers, etc., who reinvent themselves by going back to school.
I’m sorry that you find it “ridiculous” that interviewers would question two of the same degrees, but these companies invest a lot of money to train and further educate their employees, and they expect efficiency, as well as being able to qualify for security clearances. You are the one who has struggled to find employment to fit your goals. I’m giving you a heads up.
If you were ever placed in a position, to monitor/create a budget for a client, the company will need to be confident that the budget will be streamlined to be efficient and cost effective. ME’s can be put in charge of a budget when designing a product. Think outside the box and try not to be so defensive that it pushes your interviewer in a negative direction.