Different language srt subtitle won't show from time to time

I have been using Infuse and I am satisfied for the most part.

Lately I’ve been encountering problem that sometimes I have mp4 movie with srt subtitle in Thai and in English for many titles.

Some of this will show Thai subtitle correctly. Some won’t show Thai subtitle but will show English subtitle correctly.

It baffled me that this doesn’t seem to be consistent. All files are stored on my Windows 10 PC. But the problem only occurs in some of them.

Any suggestions?

Thanks in advance.

Are you saying that you have a specific movie that has subtitles that show sometimes and not others?

Do they not show as a possible selection or are they there but not matching the video or working at all?

Are the subs embedded in the file or downloaded with Infuse?

Movie1.EN.srt (english subtitle)
Movie1.TH.srt (Thai subtitle)

Movie 1 works , show Thai and English subtitle correctly


Movie 2 doesn’t work. English subtitle showed correctly, Thai subtitle is selectable but when selected the subtitle does not show

Perhaps your bad subtitles have specific tag like color or position which prevents the display.
I’ve seen this on another player.
Extract the srt file and verify.