Tin Tranagle Surface Problems

I Have a question that may be easy for most of you, I'm not sure. My issue is that I can't seem to get the TIN surface to reference all the points in the group it is assigned. I don't have any triangle length limitations on. I worked with an older version of CAD using Eagle Point and I did not have this issue. I've attached a JPG showing an example. In the upper left of the picture, I want the left point to reference the other three points. To the right in the picture is just an example I put together using five points, as you can see, it does not reference two of the points. However, in the bottom of the picture if I move one of the points over a little, it used the point. This may be an easy fix, I don't know. Thanks for you help.

Just guessing-you say there are no length limits, but are there any interior angle limits? (don't know if that is even an option)

I have thought of that also, because at sharp angles they will not reference. However, I also don't know where the setting or option is if there is one.