Hi,
Yes, I see your problem. The standard search does not contain all tweets. On https://developer.twitter.com/en/docs/tweets/search/api-reference/get-search-tweets.html you’ll note that “Twitter’s search service and, by extension, the Search API is not meant to be an exhaustive source of Tweets. Not all Tweets will be indexed or made available via the search interface.”
Where are you attempting to get the missing tweet from?
Happy holiday season 
