Why you cannot test while logged in
The account owner sees a different X than everyone else. Your own session knows you, so your posts come back in your own searches, your replies render in your own threads, and nothing ever looks wrong. Every test below has to run in a logged-out browser, a private window, or a device that has never signed in.
Clear the boring explanations first: your account is public, you are not blocked by the person whose post you replied to, and your reply is not a reply to a reply — X hides many of those by default.
Test 1 and 2: search suggestions and keyword search
Log out, open the search bar and type your handle slowly. Suggestions are built from public data. If your exact handle returns no people suggestion while accounts of similar size do, that is a suggestion-level signal — though handle popularity and spelling also matter, so it is never proof on its own.
Then search a distinctive phrase from one of your recent public posts, verbatim, in quotes. A healthy public account surfaces for its own text. Nothing at all, while older posts from the same account still appear, points at a search-level restriction rather than a content problem.
Test 3 and 4: replies under a busy post
Find a large public account's recent post, reply to it, then open that same post in your logged-out window. Your reply should be there for a stranger to read. If it is missing for logged-out visitors but visible in your own session, that is the pattern usually described as a ghost ban or hidden replies.
Replies are also re-ranked rather than removed: scroll and expand the thread. A reply that only exists far down the list is a ranking outcome, not a ban — and this is the check that produces the most false alarms.
Test 5: the second-account cross-check
Ask someone who does not follow you to open your profile and your latest post. Profile pages usually keep working while distribution is suppressed, so a working profile next to failing search results is itself useful information.
Then write down what you measured, with dates. One odd result is noise. The same result twice, two days apart, across search and replies, is a pattern worth acting on.