Identify where the subtitle is being drawn
Write down how you opened the programme: the television’s live broadcast input or the SBS On Demand app or website. Similar programme branding does not make those two viewing routes identical. A subtitle already incorporated into the picture cannot be restyled in the same way as selectable player text.
SBS’s size-and-colour help describes this distinction for subtitles. Keep that wording separate from a general claim about every kind of broadcast caption or accessibility signal. If you are using a selectable CC track, record that fact; it is a different control context from translated text that is visibly part of the image.
Check the On Demand player and platform
For On Demand, SBS says font size and colour are constrained by the platform or browser, and may be adjustable depending on that route. Inspect the actual subtitle controls exposed by your app or operating system rather than assuming that a browser screenshot also applies to a television.
First confirm that the intended subtitle or caption track is active. SBS documents a CC indicator on eligible programme pages and separate player controls for its different devices. Changing the size of a track that is not enabled cannot establish whether the track is present.
Describe the limitation precisely
If text remains fixed, record whether it appears without selecting a subtitle track and whether changing an exposed style control affects it. Those observations help distinguish video-embedded text from a selectable track whose style is limited by the receiving platform.
For a viewing alternative, check the same programme’s available On Demand edition and its language or caption options, without assuming identical availability or presentation. When contacting SBS, identify the programme, route, device and the specific text you want to enlarge. That is more useful than asking for a universal subtitle-size setting, because the broadcaster’s guidance explicitly makes the answer dependent on how the text reaches the screen.