Having tried your suggestion -- thanks! -- I would like to be more specific: The datapoint popups which create an overlay are the troubling ones. "Data point details" opens the proper link (the data point details), but the other ones show the overlay and additionally open a new tab with the link.
Even after restructuring thrice the problem description sounds odd. Apologies for that. Maybe the code helps...
<a href="http://localhost:8080/ui/watch-list/" target="pointdata">
<ma-point-value style="position: absolute; left: 0px; top: 350px; width: 90px; height: 40px;" enable-popup="right" quick-info="false" point-xid="internal_mango_num_data_points"></ma-point-value>