Reproduced with 6.2 EE SP4 :
1. Configure site to use Single Approval process for web-contents
2. Create web content folder
3. Create web content in this folder, submit content for publication
4. During publication process - "assign task to me", edit content and do some changes (for example in content text), after it save it
Now, go back to site content -> web content
Expected behavior: processed web-content stayed in the folder
But it was moved to top-level folder.
Looks like then we edit folder during approval process information about it's folder is lost.