At my company everyone has two job titles, their internal corporate one and one that describes what they actually do. For instance my internal corporate job title is Design Engineer 1B, but my business cards and email signature say Industrial Designer. Same with the mechanical engineers and interior designers who are also lumped into the Design Engineers category.
The internal title is just for HR’s organization of the company and for employees to find out where other people rank if they don’t know them. It’s much easier to say “everyone with a 1B after their title makes $X per year and gets X number of hours of paid time off each year” than figuring it out on a case-by-case basis for such a huge company with such a diverse number of different jobs and job titles.
The only person who actually calls themselves a design engineer here is the one interior designer who hates interior design and doesn’t want to be called an interior designer.