Two x-axis, one y-axis plots only last figure

I want to plot two lines. They should share the y-axis, but have different x-axis.

If I plot them separately, everything works. But if plotted together I get only the last plot instead of both, seems like last plot overrides the first one even with hold:

%% figures
figure
hold on
t = tiledlayout(1,1);
ax1=axes(t);hold(ax1);ax1.Clipping='off';
ax2=axes(t);hold(ax2);ax2.Clipping='off';
ax1.XAxisLocation = 'bottom';
ax1.YAxisLocation = 'left';
ax1.Box='off';
ax2.XAxisLocation = 'top';
ax2.YAxisLocation = 'right';
ax2.YAxis.Visible = 'off';
ax2.Box='off';
xlabel(ax1,'Speed, m/s')
ylabel(ax1,'Power, HP')
xlabel(ax2,'RPM')

%plot (ax1,V,plot_tau,'DisplayName', 'V vs τ Theoretical','Color','red')
plot (ax1,V,P,'DisplayName', 'V vs HP Theoretical','Color','blue')
plot (ax2,RPM_exp,P_exp,'DisplayName', 'RPM vs HP Experimental','Color','red')

title ('Power and Torque Ford Explorer V6')
grid minor;
legend('Location','northwest');hold off

Answer 1

[Ivan Bondarenko]

Found the problem.

Since the new axis is trying to cover with itself the figure, you need to hide the last axis (make it transparent so the first one is seen).

Added

ax2.Color='none';