Maybe it's just bad luck, bad interviewers, etc -- but are you applying for jobs that would make best use of your skill set?
Given your past experience, you sound like you'd be a good fit at a smaller company (or perhaps a small, independent team at a larger company) -- places where as an IC you're needed to make important decisions, solve problems, and coordinate directly with lots of different stakeholders, independently and without much management. You probably wouldn't be as good a fit at a large company, or a place where you're needed to just shut up and write beautiful code.
With your history, if I was considering you for a dev job, I would be mostly interested in learning more about your leadership, mentorship, program-management, product-ownership, problem-solving, communication etc skills -- if those were particularly strong, I would be excited about how I could use those skills on my development team; and I wouldn't be so much worried about your programming skills (or your ability to explain Big O etc) as long as you could show that you could solve a basic fizzbuzz problem or two.
But if you haven't been doing much coding in recent years, you should probably also sit down and spend some time working through a bunch interview-style programming questions. If you're out of practice, putting in some reps will help you get back into the groove of thinking through problems programmatically and banging out code. If you do that for an hour or two every night for a couple of weeks, that should get you back into shape (and build your confidence) so you can do at least a passable job on the coding parts of job interviews.