The checks
A real checker would need the visitor to be logged in, and Reddit does not hand that to a random website. We describe the logged-out test, the profile test, and the 'removed by AutoMod' pattern, which is what you can actually verify.
Run the shadowban checks before you blame the copy. A comment can be perfect and still invisible. The warm-up checklist is the other half: an account that is too new will lose to AutoMod even when a human would have kept the comment. Do those two by hand once so you know what Karmy is refusing to post into.
Why these are checklists
A website cannot see your logged-in Reddit session, and it should not ask for it. The shadowban check is the logged-out profile, a comment URL opened in a private window, and a search for the username while logged out. Run it before you blame the copy. The warm-up page is the other half: an account that is too new loses to AutoMod even when a human would have kept the comment.