When a list is set to display Full Content, the component's settings to Open in New Page do not apply to links that occur in those full content pages.
Published October 15, 2015
A list component can be set so links 'Open in New Page,' but when the list is just displaying pages as 'Full Content,' the component's settings are not applied to those Full Content pages. (The component does not scan the associated content for any links.)
This is normal behavior for the UBCMS and will not likely be changed.
As a workaround, please adjust the settings for the links in the associated content, and set them to Open in New Page on that end.