Interlaced material contains alternating fields from different moments. If those fields are combined incorrectly for a progressive display, moving edges can show a comb pattern. A suitable deinterlacing path is needed; simply increasing sharpness or internet speed does not correct the field relationship.
Use movement as the clue
A still studio background may look normal while a moving arm or camera pan reveals horizontal teeth. That pattern differs from square compression blocks or a whole-picture pause. Compare another programme and note whether the problem is limited to sources identified as interlaced in the player’s information.
Try supported deinterlacing options
If the player documents an automatic or alternative deinterlacing mode, record the starting value and compare the same passage. Some decoder paths handle fields differently, so a controlled decoder comparison can also be informative. Do not change several advanced controls at once and then assume the first improvement establishes the cause.
Report the source and path
Include the channel, time, device, player version and any displayed scanning information. If another supported player shows the same source correctly, mention that difference. Avoid applying a television-wide aspect or colour correction to a timing problem; it can distort otherwise working programmes while leaving the comb pattern intact.