The picture may be interlaced and displayed without suitable deinterlacing; this looks different from blocky compression or a network pause.
Why this happens
Interlaced television represents motion using alternating fields rather than the same arrangement as a progressive frame. When that material is handled poorly on a progressive display, moving edges can show a comb-like pattern. The effect often appears around an arm, a player’s shirt or a fast pan while stationary details look relatively normal. Increasing a network buffer will not directly repair that presentation issue. It is worth describing the pattern before changing the connection.
If the player offers a documented deinterlacing mode, compare its automatic setting with the supported alternative on one affected source. Do not force deinterlacing globally just because a single channel looks wrong; progressive material has different needs, and available methods depend on the device and player. Keep the source name and any player process information with the result. When the pattern follows only one version of the channel, that is useful evidence about the feed. If it affects several known interlaced sources in one player, the local playback route deserves attention.
A useful way to work through it
Look for fine horizontal teeth on moving edges rather than a full-screen pause.
Compare only a deinterlacing option documented for the installed player.
Restore the original setting and record which sources show the pattern.