1. Improper journal selection: First of all, you need to ensure that your paper is published in the journals included in SCI. Although some journals claim to be SCI journals, they are not actually included in SCI. So you need to confirm whether your journal is really included in SCI.

2. Publication delay: Sometimes, due to various reasons, the publication of periodicals may be delayed. This may lead to your paper not being retrieved by SCI for a period of time after publication.

3. Data submission delay: If your paper contains some data that needs to be submitted through the data submission system, the delay of this system may also lead to your paper not being retrieved by SCI for a period of time.

4. Retrieval delay: The update of SCI database is not real-time, but there is a certain delay. Therefore, even if your paper has been published in a journal, it may take some time to be retrieved in the SCI database.

5. Indexing error: Sometimes, due to various reasons, there may be indexing errors in the SCI database, resulting in your paper not being correctly indexed. In this case, you may need to contact the journal editor or SCI database administrator for their help.

6. Quality of articles: If there are serious quality problems in your papers, such as plagiarism and data fraud, then the journal may refuse to publish your papers, and naturally it will not be retrieved by SCI.

Generally speaking, the failure to retrieve SCI articles after publication may be caused by various reasons. You need to take corresponding measures to solve this problem according to the specific situation.