sidebar creates new submenu and keeps the old one

snippet: https://snippet.webix.com/s6ikzzhs

If the sidebar is not expanded, every time you hover over Tree and lose focus of the sidebar after, a new submenu is created in the dom and the old one is kept. this leads to unnecessary elements.

Hello,

Yep, I can confirm the issue, thank you for reporting. We will provide a fix in the next update.