Buopoth not capturing ships

This is the second game in a row where he Buopoth is not capturing ships even though the description says it has a100% capture rate. 
Here is the save file.  Please let me know what I need to do to repair my game.

 

https://1drv.ms/u/s!AgJMBDlu0Hg-gYZVYBSt1RDPsocLSg?e=QChmfH