Apple TV 4K embedded subtitles size can't be changed?

I use a 2021 apple tv 4k. I would like to change the size and lettertype. I did change in the settings of the apple tv itself. And if I download a subtitle from opensubtitle in infuse the subtitles are as I set them in the apple tv settings. But if I use the embedded subtitles which came within the mkv file I can’t change anything.

Problem is the option of “other” when selecting subtitles, which download from opensubtitles is not alway’s working. So I have to use the subtitle from the movie file. Don’t know why sometimes I can’t download from opensubtitles? Infuse tells me to check the internet connection but there is never a problem with my internet connection.

Is there a way to change subtitels within infuse?