because my test video is 2:30
So, to check again, I have to start from the beginning

As you can see, subtitles work the same way in two video players.
Different image aspect ratio gives subtitles a different scale and spacing, but colored words overlay white words without shifting.

So, we have the problem: These subtitles do not work correctly in Emby Theater.

The solutions:
1. Use a different video player for such videos.
2. Change subtitles or renderer settings in the Emby Theater application.
3. Send a bug report to Emby Theater developers if the subtitles still do not work properly.

from what i've seen from your screen shoot, your light fill is on the top and bottom, not the side (left and right) since the effect is not horizontal, i do think it wont have problem, so it's fine that way
BUT if you use it on ultra wide, like mine for example, 3440x1440 the problem will appear

any 1080p video you play would have black border in left and right, and it will stretch the subs when in full screen (will make spacing issue but it's fine atleast for the opening section)

on another note, kindly try the subs in minute 20+ that's the main problem
i've just checked the early minute / opening is fine without issue (only spacing issue which is minor to me)

the problem appears there

So, we have the problem: These subtitles do not work correctly in Emby Theater.

The solutions:
1. Use a different video player for such videos.
2. Change subtitles or renderer settings in the Emby Theater application.
3. Send a bug report to Emby Theater developers if the subtitles still do not work properly.

mpv player.

Maybe it is a combination of hardsubs and softsubs overlay?
Try to disable subtitle output at thi svideo. Do you see any text at the bottom of the screen?

it's soft sub (no sub at all when disabled), the normal subs is fine (without effect) but if it's with effect like the vids shown, it will stretch (this is applied for all softsubs with karaoke effect i have tbh, it just i reported it just now, kinda late tbh)
if you want the source, you can try it there (need ultra wide monitor first and in full screen), the source is [SobsPlease] Girls Band Cry - 11 (1080p)
or if you want just the subs without other attachment, it's in here https://drive.google.com/file/d/1CIIp6E … drive_link

Looks like it is a subtitle renderer issue.
I see dynamic subtitles on your video.
I know that MPC-HC player can display such subtitles correctly.
Which video player are you using?
Have you tried changing the subtitle settings in your player?

i used emby theater, which used libmpv, so i can hook svp4 there
pic of emby settings : https://i.imgur.com/iNZdWac.png

as for the MPC-HC version, i didnt touch any subs filter config though, since my primary player is emby theater (all my videos in emby server), it's same output (same error), here the recording
https://drive.google.com/file/d/1B_YV84 … deG9H/view