strange unconnected pins

 I have a very simple desige, only have few compnents. I noticed that in the unconnected pins report have many pins that connected.

the design used to be 16.2 or even early version. I upgrded to 16.6 recently. 

if I delet the trace, I couldn't reconnect to the unconnected pins.  but if I check the net, it shows the pins are in the same net. 

for example

ZTP7.1 to L2.2 marked in the attached picture.  How can I make the connection between this pin?

thanks,

David