Autodetect constantly adjust zoom if the video changes

[IIARROWS]

Describe the bug
Autodetect constantly changes the zoom if black bars are part of the picture and they appear and disappear, causing an annoying effect and hiding content when it appears, for example subtitles, losing important context.

A few examples as these is in movies or documentaries when a character/person speaks another language, which is appropriately hardsub on a black area if it's there, to avoid putting the text on the scene and for better contrast.

To Reproduce
This video is a good example of the behaviour:
https://www.youtube.com/watch?v=l_jlEKab39s

It's composed of two bars where the lyrics of the song are displayed, when there is no singing one or both are empty and autodetect changes the setting, hiding the bars but not restoring in time when text appears.
In this specific case is annoying because it's constant, but I would say it's an exception and not the use case I'm talking about.

Expected behavior
The video zoom level shouldn't change constantly, if something appears on the black area, it shouldn't hide it anymore when the content disappear, as more could appear later.

Version: 6.0.0.1

Additional info
There could be an option to force autodetect only at the start (a few seconds), often video that are meant to have black bars with content start with a logo in 16:9. Content that is filmed in ultrawide formats don't put content outside of the viewable area, so if it starts with black boxes and stays that way for a few seconds, it could be safe to assume no content is going to appear later.
If it doesn't start with black boxes, such as a studio logo, it's probably meant to use the black space later on.