Security Engineer can be applied to a lot of positions.

It can be used for security oriented developers, I've worked with some companies where they had their normal devs, and then some devsx were security swe and those were responsible for the security aspects of whatever project and were a point of contact for questions, and often had to sign off on certain types of changes. So those guys would be SWE with a security focus.

On the other hand, I've held the Security Engineer title and did little development (though I have a dev background). Instead I performed security audits and code reviews, consulted with teams about their planned security implementations but would generally stop short of any real development outside of tools I was writing for myself/team.

I know Microsoft and Amazon both have Security Engineer/Security Software Engineer positions those positions are both (in my experience) like the position I described having held, emphasis on Security rather than Software Engineer.

Though I've also seen the Security Engineer title applied to someone reading logs and alerts in a SoC and to a network pentester.