Doubled system tray icons in Xfce

I have Red Hat based system with Xfce DE and installed Skype last version from official site. When I running it (only once, with one user account) in system tray I seeing doubled Skype icon, and not only Skype as you can see on the screenshot. **How to get rid of the icon's duplicate?** --- ### My systems: - RHEL 7.5 - Centos 7.5 - Xfce 4.12 - Skype 8.28 - Telegram desktop 1.3 Latest software for today..