Breaking a wire creates two segments of wire that are no longer connected to each other. This is because EasyEDA automatically assigns different netlabels to each end of a broken wire. To rejoin the connection, add netlabels with the same name to each segment of the broken wire. NetPorts and NetFlags can be placed anywhere on a net but take care that the little grey connection dot is placed onto the wire. To avoid accidentally connecting nets together that are not intended to be connected when manually assigning netlabels, take care to ensure the netnames assigned are unique to each net. For example using the name 'mid' instead of 'ammeterneg' would connect the negative side of A1 to the 'mid' net and would short out R1.