Weird 3D Scatterplot results

The first image has this code attached to it: ```filenameLR2 = 'LR2-1.xlsx' data_LR2 = pd.read_excel(filenameLR2) XY = data_LR2[['X', 'Y']].values Z = data_LR2['Z'].values model=LinearRegression() model.fit(XY,Z) print("Model Coefficients: ", model.coef_) print("Model Intercept : ", model.intercept_) model.score(XY, Z) x_fit = np.linspace(0, 21, 5000) y_fit = x_fit z_fit = model.predict(np.column_stack((x_fit, y_fit))) fig = plt.figure(figsize = (16, 9)) ax = plt.axes(projection ="3d") X,Y = np.meshgrid(x_fit, y_fit) Z = 0.54079386*X + 0.39793276*Y - 30.477902526663 ax.scatter3D(data_LR2['X'], data_LR2['Y'], data_LR2['Z']) ax.plot(x_fit, y_fit, z_fit, color='red') ax.plot_surface(X,Y,Z, color='red', alpha = 0.4) plt.title("simple 3D scatter plot") ax.set_xlabel('X-axis', fontweight ='bold') ax.set_ylabel('Y-axis', fontweight ='bold') ax.set_zlabel('Z-axis', fontweight ='bold') plt.show()``` And I'm trying to replicate what the second image (example) looks like but it keeps turning into this weird straight line.