There's no option to pin the window when I use tracking

[rediffusion]

When I add a new one it goes all the way to the end\top.
I want to pin some of my favorite tabs.
screencast

Before:

After:

Take care 😎

[rediffusion]

I have a session with 4 tabbed windows. If I enable "Tracking" and then open one window it changes location. Sometimes it goes down to the very bottom and sometimes up to the very top.
NOTE: Only the window at the end or up after opening remains at the end\top.

screencast with the moment when the window goes down to the very bottom. At this moment I can't catch the moment when the window goes to the very top. Maybe I can show it soon...

UPD #1:
I noticed something else:

1. When I click on the first window sometimes it goes randomly to position 2 or 3.
2. Sometimes no matter which window was clicked it's stuck! Like if I used the pin option.

UPD #2:
I've tested and found that when I ran Firefox first time. That I open randomly window 1-2-4-3, it's pinned you know! But after several attempts 5-7. The windows start to curl up at the end\top.
And like I said before Only the window at the end after opening remains at the end\top.
TBS minimized or maximized it's no matter, same shit everywhere. 😕