Created attachment 111983 [details] screenshot open dolphin click "network" in the side bar select "Add network" icon
Does the icon return if you turn off inline previews? (click the "Preview" item in the toolbar)
no, it remains invisible.
Do you have previews turned on for text files in Settings > Configure Dolphin > general > Previews?
No.
Confirmed: missed the "when selected" part of the Summary. Looks like possibly an issue with the "knetattach" icon.
*** This bug has been marked as a duplicate of bug 398014 ***