When the "Show icon preview mode" is engaged in the Finder, the process of generating those previews interferes with file or folder renaming. Selecting an item and seeking to rename it by clicking the text frequently deselects or "jumps out" because the icon generation for other items in the same folder is ongoing. You have to wait until all icons are generated before the text selection "sticks" and a new filename can be typed. When trying to rename a single item in a large folder, the process can be short circuited for a minute or more until icon generation completes.
The background process of icon generation should be threaded and should not interfere with any other operation, including renaming.