SUMMARY
Yesterday did an update, I think it updated qt to 6.9 and perhaps some kde framework and also kwin. Today I noticed that Dolphin window icon uses file manager icon instead of Dolphin icon, which is specified in its desktop file. 

STEPS TO REPRODUCE
1. Use Papirus icon theme (Because in Breeze Dolphin icon matches system-file-manager icon)
2. Open Dolphin

OBSERVED RESULT
In app launcher and on the panel it has Dolphin icon, but window decoration has system-file-manager icon, and the same with alt+tab menu

EXPECTED RESULT
Everything should either use system-file-manager icon or Dolphin icon. Preferably, the one specified in the desktop file.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.9.0
Kernel Version: 6.14.0-zen1-1-zen (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 5600H with Radeon Graphics
Memory: 13.5 GiB of RAM
Graphics Processor 1: AMD Radeon Graphics
Graphics Processor 2: NVIDIA GeForce RTX 3060 Laptop GPU

ADDITIONAL INFORMATION
Papirus theme: https://github.com/PapirusDevelopmentTeam/papirus-icon-theme. In Arch extra repo it's papirus-icon-theme