Zero-width space appearing in Alt Tab when sidebar is hidden

[Keagel]

Hello!

This may be only MacOS related since I'm not seeing anyone else reporting this. I'm using Contexts instead of the native Alt Tab behavior on MacOS and when the sidebar is completely hidden (using the shortcut from Userchrome Toggle Extended) an unicode character appears in the window title:

I've managed to extract the window title and found out it's a zero-width space. What is its purpose in the window title?

Between the arrows: =>᠎<=New Issue · Naezr/ShyFox