Wrong subtitles position for specific movie aspect ratio LE 10 Allwinner H6

I have a problem with the subtitle position (Allwinner H6 Tanix TX6 + LE 10.0.2). I'm fresh on LE 10, so don't know this is old or new bug.

I am not able to change its position with the setting "fixed" for x265 codec. When playing x264 video subtitle position follows calibration settings. In cause of x265 video - not.   <-- wrong conclusion, more in next posts

I used to change the subtitle position with the video calibration settings when playing a video. That is possible and I see the subtitle move when doing the calibration (calibration settings is on screen). But when I press back (and calibration closes), the position of the subtitle did not change (return to bottom of the screen). The position with the calibration is saved though. When I go back to video calibration, the subtitle line is still higher.

Trying this with and without PRIME, the problem occurs in all combinations.

I did more tests and I was wrong. The problem is not the codec, but the video aspect ratio.
Incorrect subtitle position occurs at aspect ratio 1.85:1, 1.78:1.

For example video aspect ratio 1.78:1, subtitle position on video calibration settings

and same text but position much lower (below bottom of movie) after closing settings

I haven't found the problem (so far) when the aspect ratio > 2:1

Quote from Pretoriano

There's a PR for Kodi that might be related to your issue! Do you have overscan set? - > https://github.com/xbmc/xbmc/pull/21026

It is not related. This is fix for Kodi 20 (Nexus).

I checked, the problem also occurs on LE 10.0.1.
I used RPi with LE9 (Kodi Leia) before and there was no problem.

I checked VM version of LE 10.0.2 on my PC also, there is no problem here.
So this is related to hardware I think. Allwinner H6 version?

I found it happens when player's playback "Adjust display refresh rate" is set to "Always".