Duplicate edges not supported after using unique

Hello community, I'm comparing two graphs, I'm able to plot the first graph fine and afterwards i sort the data in the table to replot the secod graph. I use unique to eliminate any duplicate rows in order not for the error duplicate edges not supported to show up but for some reasons it still throw the error duplicate edges not supported. Code is below:

a = 1:2637;
NewEdge(a,1) = sort(NewEdge(a,1));
b = 1:2637;
NewEdge(b,2) = sort(NewEdge(b,2),'descend');

%NewEdge(:,1:2) = sort(NewEdge(:,1:2));
NewEdge = unique(NewEdge(:,1:2),'rows');  %eliminate duplicates
GG = graph(NewEdge(:,1), NewEdge(:,2));      % create a graph from A
d = degree(GG);
notConnected = find(d < 2);                    % weakly connected nodes
d(notConnected) = [];                             % drop them from deg
GG = rmnode(GG, notConnected);                        % drop them from graph
figure   % visualize the graph 
plot(GG);
title('Power Grid, After movement')

[Guillaume]

Which function throws your duplicate edge not supported error? plot has no problem plotting graphs with duplicate edges.

Note that if you want to remove duplicate edges in a graph, the simplest way to do that is:

%remove duplicate edges from graph g
g = graph(unique(g.Edges));

[Isaac Osei Agyemang]

Okay Guillaume, thanks you very much.