Why happen this issue? I remember no happen no issue with Dolphin version 24.08 ago.
Focus move to 1.left view next 2.right view next 3.left view next 4.right view tab.
I want get to old Dolphin 24.03.
 
This issue is why not Critical?
1.If you press Delete key on right tab, But Dolphin does'nt remove file on right tab view, Dolphin did remove some file on left tab view.
2.If you press Cut(Ctrl+X) key on left tab view, But Dolphin do cut file on right tab view.
or Dolphin ask you. "Selection mode ?  x Exit Selection Mode" =(

So you can't to you want some action to Dolphin some file, Some directory on you want left or right view panel.
You near lost data of you important file or you important directory with this happen.
Focus go to reverse view panel. If I want some action to left panel view, But focus go to right panel view. Really I don't know why happen.

I checked get happen action is what. Maybe important reproduce method, Lost focus Dolphin.  
So I clicked other program, Desktop, exept dolphin. Next need focus Dolphin, clicked some view panel or toolbar. 
Action of Alt+Left(Back) or Right(Foward) or Up.
If Back action. Back action did right view panel, Next back action did left view panel. Crazy.

Why add focus issue on Dolphin 24.08 after? What commit happen this?

I know fixed commit info is in [https://bugs.kde.org/show_bug.cgi?id=508554] 
But doesn't fixed probrem that commit. I build and use dolphin 26.03.70. This version have focus panic too.

Dolphin:26.03.70
Operating System: EndeavourOS 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.14.0-rt3-arch1-5-rt (64-bit)
Graphics Platform: X11