Electrolux washer- motor pulley rotates but drive belt does not move
This is probably the bearing of the drum wearing out.

As it ages it gets stiffer, requiring more force to rotate the drum.  The whining noise is as the belt and bearing get hot slipping against each other.

Drum bearings aren't easy to replace, and on some machines, impossible.

Try packing some grease into the bearing, trying not to get any on the belt of course.