Ensure you match the subtitle to your movie version. The Extended Cut (approx. 151 minutes) has different timing than the Theatrical Cut (approx. 144 minutes). If the text appears on screen too early or too late, you likely have a mismatch between these versions.
If you're looking for help with the subtitle file for , specifically the 1080p.x264.BluRay release, Finding the Correct Subtitle subtitle The Martian 2015.1080p.x264.Bluray-Har...
For a rip like the one you mentioned, you should look for subtitles tagged with SPARKS or BLOW , as these are the most common scene releases for that specific 1080p x264 encode. Popular platforms where you can find these include: Ensure you match the subtitle to your movie version
: Often hosts direct downloads for specific release names. specifically the 1080p.x264.BluRay release