Use the search field in the module you are viewing: Posts, Intelligence, Bots, and Target URLs do not necessarily search the same fields. Start with one distinctive word from the title, message, URL, account, or shortlink, then add an exact phrase or other filters only when the result set is too broad.
Check the date range, brand, social network, status, author, tags, and selected theme because the keyword search is applied together with those filters. Clear all filters and try a shorter spelling before concluding that an item is missing. Accents, translated text, shortened URLs, or content retrieved from metadata can differ from the visible wording you remember.
For a reproducible support request, provide the module, keyword, active filters, timezone, expected item and approximate date. Do not send private content that is unrelated to the search problem.