Hi Ron,
Thanks for getting back to me on this. I have created a copy of the project with detail below and shared the project with you as co-author on our Xerte setup.
Name: Section IDs Test
ID: 20441
In the example project, I have added a group of links using the internal links function to link to different sections. I have also added a unique section id to "Creating a Test" section. As you can see, the internal link for that section doesn't work anymore once the section id been added. The rest of the links work fine.
Thanks again for looking into this.