TextMesh Pro TMP_TextUtilities.FindIntersectingXXX always returning -1

I´m trying to code a clickable link feature for TMP. After failing several times I found out that the FindIntersectingXXX Functions always return -1 for me. I tried an empty scene with a new canvas and TMPUGUI component but it still fails for me.

any Ideas on the Problem?

Code (CSharp):

1. private void Update()
2.     {
3.         int wordIndex = TMP_TextUtilities.FindIntersectingWord(tmp_text, Input.mousePosition, Camera.main);
4.         int linkIndex = TMP_TextUtilities.FindIntersectingLink(tmp_text, Input.mousePosition, Camera.main);
5.         DebugPanel.Log("wordIndex", wordIndex);
6.         DebugPanel.Log("linkIndex", linkIndex);
7.     }

Unity Version: 2017.3.1f1

 

I pass null for the camera but the app does nothing when I click on a link. The code works when linkIndex != -1 but it's like the script stops working when I do click on a link.

The variable linkIndex doesn't even get a value when I click on the link. I set a breakpoint on the line and I can't get any value, it's as if the code just doesn't execute anymore.

EDIT: nothing to do with the script, sorry. My link was at the bottom of a viewport and clicks aren't being registered there. That's another issue I have to figure it out now