Now in threaded view when a thread is collapsed, you will only see a star icon for the thread if you have stared the first mail of the thread. (See pics attached) A more intuitive approach of it might be “showing a star if you have stared any mail of the thread”.
Also, if you star a collapsed thread, you are actually staring every mail of the thread. So I guess making the above change will make the UX logic more consistent.
Thunderbird Version: 128.4.3esr