BS, MS engineering w/good GPA, 3 internships, only 2 calls, no interviews, 500+ applications, 18 months unemployed, out of ideas

To be up-front: this is a cross-post because I feel maybe this subreddit is a more appropriate place to post.

I feel that clearly I'm doing something wrong. The problem is I've consulted hiring managers, other engineers, career counselors at universities, gone to job fairs and networking events (with connections and followup afterwards), and I just get statements like "this looks good" and "just keep going." None of these things are helping. I refuse to attribute these absurd odds to "bad luck." I did my part and worked my butt off in school and did the relevant internships, going through grad school on a scholarship for free. I understand that the world doesn't owe me anything. I just didn't think the odds would be this bad.

I've taken so much advice from so many people around me that I've run into tons of contradictory advice, which is to be expected because everyone's story of getting employed is different. I experiment with every combination of the suggestions I've been given to see if it nets me anything. I'm getting referrals from friends, people within companies and the comments I get back are the same thing, "this candidate has strong credentials but we have no need for X at this time" or "this candidate needs more job experience" or the hiring managers just get caught not even looking at resumes when they were assigned that task. The degrees are in aerospace engineering, and I did an internship working for a government contractor for Northrop Grumman, an internship working for a NewSpace company (was "promised" a full time position at the end of the internship and then they just pretended like they never did so, then the company tanked), and a year long internship at one of the NASA space centers.

GPA is 3.5 for both BS and MS.

I apologize in advance if I tell you that I've already done something you suggest. The amount of things I've done are just so numerous and varied that it would be tough to recall everything I've done and list it all here. Basically I've done the customizing of resumes and cover letters, done the whole "keyword" thing so the search engines find a strong match (the resumes kept rating mid 9's or perfect 10's on this "Resunate" service someone gave me), networked with friends around the region and country forwarding my resume to them and having them forward said information to the company internally, etc. I actually got an interview invitation to Lockheed Martin last year, and they were going to fly me out and everything. I maintained communication with them by phone and email and submitted all the documents they were looking for, then they just stopped responding. I left emails, messages on the phone, tried going to higher ups, and never got a response. It was like the whole interaction just vanished. This was during the internship at the newspace company and they had just assured me that everyone got hired onto said newspace company by first doing an internship. I built, from the ground up, working hardware from the structural analysis, making of the raw material cutting, part welding, part machining diagrams, tracked down relevant machinists to build the specialized parts, negotiated discounted prices for the company, and had the part built, and the part worked. After my internship was over, I only found out that the part was successfully tested after a friend of mine from the other side of the world forwarded me the news.

I don't know. I'm at a loss here. I'd understand if I was at least getting interviews and failing those. That would indicate some kind of personality problem that I could work on and try to improve. In this case, I'm not even getting those initial calls. It's really weird.

I am not limiting the search to aerospace companies. I'm applying to a wide variety of industries, from server hardware, medical hardware, software companies (I have programming experience), construction companies, etc. I'm trying to keep the search as focused as possible but it can be difficult. Most of the hope I have rests on the relationships I'm building and what they can do via referrals.

At this point I have a feeling the biggest reason why I'm not getting any calls now is the unemployment bias, but I've done much to mask that fact by including tasks I'm doing as a volunteer for companies that are very much engineering tasks (while not saying the word "volunteer").

Something just feels very wrong here. Surely I should at least be getting calls with my degrees + internship experience, right? Maybe not? I'm no longer touting the usefulness of engineering degrees because I did everything that my instructors suggested and I still feel like I'm treading water unemployed, in an endless cycle of doing more personal projects to put on the resume, getting certifications. I'm not even in a region that's struggling for jobs. I've moved between the two hottest engineering hiring regions in the country.

Right now I'm actually earning money through artwork I create, since I'm not exactly netting anything on the engineering side other than certifications and more resume tweaking via personal projects.