What fallacy is this?

This is regarding the meme that Bernie Sanders is unfit to be president because he never had a full time job before he became a senator 40 years ago.

Person B works as a professional in thing C for 40 years.
Person A claims person B doesn't know anything about thing C, because person B didn't have a job before he started his career in thing C 40 years ago.
Person A concludes, therefor we should not us person A for thing C.

Is this a non-sequitur?

Further analytical analysis on this would be helpful.

Thank you

The syllogism seems nonsensical and confused. Maybe you need to clarify it because it makes a different claim than the opening statement.

This is regarding the meme that Bernie Sanders is unfit to be president because he never had a full time job before he became a senator 40 years ago.

This doesn't seem to qualify as a fallacy as there is no perceivable deception involved. It may be a ridiculous opinion, but little more than that. However the syllogism makes a different claim:

it starts out with a fact about Person B working for Thing C for forty years, but then builds a case against Person A not being qualified for "Thing C". This is not so much a glaring derailment. but a wildly invalid argument altogether.

Yes, I would say that's a non-sequitur because I don't see a link between a person's job status before being a senator and their adequacy for presidency, and any conclusion about the person's adequacy for presidency that's based on the premise of their job status before becoming a senator is a conclusion that does not follow from the premise, thus a non-sequitur.

Some voters might think that full-time work experience is a qualification so the candidate will understand day to day life. That is not unreasonable. That is a personal choice by the voter. I don't see it as a fallacy.

In the U.S. the "qualifications" are relatively clear.
Born in the U.S. At least 35 years of age. And upon making their views known to the public prior to the election has become known enough that people cast their vote in support of. That's the only qualifications in our democracy. Anyone forwarding an agenda that includes more should be questioned as to where they have come across these "other" qualifications.

I think there could be a few fallacies here but the one that springs straight to my mind is a kind of ad hominem fallacy. A person's circumstances some decades ago are irrelevant to the current validity of whether or not they're suitable to be President.