S6 parallax background here, then gone.

[olrebbie]

lots of folks had this feature since 2015, but I didn't. it suddenly started working three weeks ago, worked for four days, now still appears 3D-ish but only moves a little vertically, not horizontally. have flicked the "off/on" buttons in Settings to no avail. whattaheck? (Samsung s6 6.0.1 Verizon.)