Sayonara has Wayland generic icon in title bar and alt+tab menu when running on Wayland session of KDE Plasma

Version

e.g. 1.7.0-stable3

Where did you get Sayonara from?

Arch User Repository (AUR)

Desktop environment

KDE Plasma

What's not working

Sayonara has Wayland generic icon in title bar and alt+tab menu when running on Wayland session of KDE Plasma. Maybe this link can help you fix this issue:
https://community.kde.org/Guidelines_and_HOWTOs/Wayland_Porting_Notes#Application_Icon

What do you expect?

Sayonara icon instead of Wayland generic icon

How to reproduce?

1. use a distribution with KDE Plasma desktop environment
2. start Plasma Wayland session
3. open Sayonara (observe Wayland generic icon in the upper left corner - see the screenshot below)
4. press alt+tab and hold alt key (Wayland generic icon is also displayed in alt+tab menu)

Did this ever work? If yes, which version was the last version without the issue?

I don't know.

Screenshot showing Wayland generic icon in the upper left corner.