When I open a new window or tab in Dolphin the icons and the navigation tree is gone, when in details view.
If I change to icons, then back to details they show up. So I’m pretty sure it’s not a setting, but some form of bug. But I have no clue where, or how to do a work-around.
Been like that for 2-6 weeks (sorry I can’t be more specific on the time).
Updates haven’t helped.
Not having this issue right now, but I use my custom Breeze + Tela icons.
So, try this:
Close Dolphin
Change your icon theme to anything else and apply
Log out then log back in and change it back to what you had before (looks like Breeze)
Log out and log back in
Note: If you are using a custom/downloaded icon theme, then try just switching to Breeze in case it’s a compatibility bug with other icon themes to test.