Dear James,does this problem happen in Movies and TV?
If so, try restoring the application;
Press Windows key + I and access Applications;
Select Movies and TV from the list and click on advanced options;
Scroll down and click Reset;To enable closed captions:
On a Windows 10 PC that is playing a video, right-click or tap and hold anywhere on the video. A menu bar will appear at the bottom of the screen. If closed captioning is available, a CC icon will be displayed.
Tap or click on the CC icon.
Tap or click the language in which you want to see closed captions. Closed captions will now appear on the screen.
Note If closed captioning is not available for the video, a pop-up window will display “Not Available”;
I hope I helped, see you soon!
No, I am using the recent released Disney+ App, that uses CC. When I made a change in the CC Settings, it shows up at the next subtitle, but the Caption Effects doesn't work. Even in the preview of the CC in the Settings doesn't update, so it is not a problem of Disney Plus, but a problem of CC in Windows 10 in general