Why does my TV picture look like a soap opera?

The effect comes from motion interpolation, a feature enabled by default on most televisions and given a different marketing name by every manufacturer. The television generates artificial frames between the real ones to increase apparent smoothness, and on filmed content the result looks unnaturally fluid, resembling video rather than film.

The reason it looks wrong is that film is shot at a low frame rate, and that frame rate is part of how it looks. Television drama and daytime programming were historically shot on video at higher frame rates, which is where the description comes from. Interpolating a film to a higher rate makes it resemble the thing people associate with cheaper production.

It also introduces artifacts, since the invented frames are guesses. Fast motion and complex scenes produce distortion around moving edges, and it adds input lag, which matters for gaming.

Turning it off is the fix, and the setting is usually under picture options with a name involving motion, clarity or smoothing. Some televisions offer a granular version separating judder reduction from blur reduction, where a low judder setting removes the worst stutter without the artificial look.

The simplest approach on most sets is to select a picture preset intended for accuracy, commonly labelled filmmaker, cinema or movie mode. These disable interpolation along with several other processing features and are generally much closer to how the content was intended to look.

It is worth noting the setting is often per-input or per-source, so disabling it while watching a streaming app may not affect a connected console or player. Checking each input separately avoids the confusion of it apparently returning.