I tried to search and found the similar issue , but I can make sure that the "New Folder" command is available for my Document Library/List. I tried to edited the view to set to first sort with column Type (Icon link to document) but still helpless.
The system Document Library (Documents) have no such issue, but the manually created Library/List have this issue.
Any ideas will be helpful. Thanks very much. Are there any settings for site collection/List/Library may impact the sort result?
BTW, I used the SharePoint client object model (CSOM) to create the List/Library, so if it maybe an bug of CSOM? The list/library created manually have no such issue. If there are an known issue in CSOM on this part?