-The similarity of papers is relatively high: it may be because some documents cited in the paper are similar to other documents, which leads to the high similarity of papers.
-The paper format is not standardized: it may lead to the failure of paper detection, because the paper duplicate checking system is mainly based on the paper format and typesetting.
-The pictures and tables in the paper can't be recognized: this is because the paper duplicate checking system can only recognize words, but can't recognize pictures and tables.
-The paper duplicate checking result is inaccurate: This may be because the duplicate checking system for waste paper is not accurate enough, or the database of the duplicate checking system for waste paper is not comprehensive enough.
-The results of paper duplicate checking are too strict: This may be because the threshold set by the used paper duplicate checking system is too high, which leads to all duplicates being judged as plagiarism.