Stack Overflow is the most popular question-answer site which is widely used by developers to solve technology-related queries. This is a community-type knowledge-sharing site where you can share your ideas and help each others.
ChatGPT works on OpenAI's GPT-3 language model. Users are blaming the tool has some flaws to give the correct answers of prompts queries.
It was so fast in beginning including generating new code & fix bugs. But slowly it has started to give plausible-sounding but incorrect or nonsensical answers.
Providing the little bit wrong answer is the main reason to being ban of chatgpt by Stackoverflow. Users who are looking for the correct solution in coding, get a prompt answers that can be a little bit wrong. People are providing the answer with the help of this tool without correctness.
StackOverflow imposed the temporary ban because answers created by ChatGPT are "substantially harmful" both to the site and to users looking for correct answers.