Earlier quoted context omitted.
Not being able to have an interview is a red flag. Companies can't tell the age from a resume. If they can, take off the date of birth, remove the year on your degrees and don't list experiences beyond 20 years.
I've been given this advice and I'm skeptical. You can only mask things to a certain degree, it can make you look like you're hiding something (which you are), and the hiring manager will figure it out soon enough in any case. If they really want to age discriminate you're probably better off finding out sooner than later anyway. In any case, later career jobs tend to come from personal networks anyway. My resume was…
It's really bad if a resume never pass the first screening, it literally can't get a job. It's not reasonable to blame age for that, interviewers cannot guess the age from just a resume (and if they can they shouldn't let be).