• This is a bug since version 14.0 or version 14.1.
• Rationalize the plot data.

DiscretizeGraphics[Rationalize[plot, 0]]

• This is a bug since version 14.0 or version 14.1.
• Rationalize the plot data.

DiscretizeGraphics[Rationalize[plot, 0]]

• Another working around is extract the plot data.

coords = Cases[plot, GraphicsComplex[p_List, rest__] :> p, -1][[1]];
polys = Cases[plot, _Polygon, -1];
GraphicsComplex[coords, polys] // DiscretizeGraphics