There are so many publications claiming that it has been isolated.
Indeed, there are many publications claiming that the virus has been isolated. This claim is usually in the title of the article, in the introduction or in some press release. However, if you look at the methodology section of the publication in question – and THAT is what you should do when you read a scientific paper – you can immediately see that none of the actual requirements that meets the criteria of isolation have ever been fulfilled.
The methodology has been questioned