Cfrgtkky

I'm trying to shade the feasible region ABCDE but for some reason, only get a weird line. This is the code:

begin{tikzpicture}

% axes

begin{axis}[axis on top,smooth,

axis line style=very thick,

axis x line=bottom,

axis y line=left,

ymin=0,ymax=17,xmin=0,xmax=17,

xlabel=$x_1$, ylabel=$x_2$,grid=major

]

% constraints

draw [name path global=xaxis] (0,0) -- (17,0);

draw [name path=yaxis] (0,0) -- (0,17);

addplot[name path global=firstline,very thick, domain=0:17]{6-0.5*x};

addplot[name path global=secondline,very thick, domain=0:17]{3+0.5*x};

addplot[name path global=thirdline,very thick, domain=0:17]{16-2*x};

addplot[name path global=fourthline,very thick, domain=0:17]{7};



% feasible area

fill[name intersections={of=xaxis and yaxis,by=point1},

name intersections={of=secondline and yaxis,by=point2},

name intersections={of=firstline and secondline,by=point3},

name intersections={of=firstline and thirdline,by=point4},

name intersections={of=thirdline and xaxis,by=point5},

][very thick,draw=orange,pattern=crosshatch dots,pattern color=green!60!white](point1)--(point2)--(point3)--(point4)--(point5)--(point1);



% intersection points name        

node at (axis cs:0.5,0.7){small{$A$}};

node at (axis cs:0.5,3.9){small{$B$}};

node at (axis cs:3,5.2){small{$C$}};

node at (axis cs:6.8,3.9){small{$D$}};

node at (axis cs:8.2,0.7){small{$E$}};



end{axis}

end{tikzpicture}

Most of the code is taken from one of the responses (cmhughes) here:
How to draw the region of inequality?
Thanks for any insights.

EDIT: Following marmot suggestion, I've added pgfplotsset{compat=1.15} (or whatever version supported) to the preamble and that solved the problem.