xfce4-panel v4.16.0 doesn't show qasmixer (qastools v0.23.0) notification balloons

qastools is here https://gitlab.com/sebholt/qastools My OS is ArchLinux GNU/Linux

On xfce4-panel v4.14.4 all is working good. Icon is in the systray, notification balloon is showing.

On xfce4-panel v4.16.0, icon is in the systray as well, but no notification balloon is showing.

Steps to reproduce: 1.install qastools 2.run qasmixer 3.check that checkbox in the settings (File->Settings->System tray->Show balloon on a volume change) is marked 4.change volume by media hotkey or hover on the icon by mouse pointer

Notification Balloon should be shown.