I auto-trained to 48, and only after that raised stealth. Use the Uthgard character builder, spec an Infiltrator however you like ( adding 77 points for the equivalent of auto-train). If you could /make 50 an Infiltrator, you would not be able to use that spec ( due to missing points).
I remember one guy who full respec just before lvl 48 and leveled up and thought he got the full AT points from lvl 1 to 48 without doing the work.
Then made a request saying it was a bug and that he did autotrain from 1 to 48.
https://www.uthgard.net/forum/viewtopic.php?f=9&t=45816&hilit=+autotrain
Never /respec once. Once 50, due to lack of points, purchased respec stone, used respec stone, and still lacking points according to all character builders. Second Infiltrator is training stealth until 40, when I will use a single-line respec.
Many posts on the forum about how autotrain works. You have to autotrain each level, not only the last level. If you full respec, you will spend 77 points in stealth automatically, that is not autotrain, it steals points from your base pool of point if you did not autotrain, which is why autotrain is almost mandatory for specific specs.
Did you /respec at any give point while leveling 1-50?
A character builder displays an auto-trained Infiltrator should have the equivalent of 3706 points, in-game awards only 3694, lacking 12 points.
Have you checked your skill in stealth? you should have skill 12 (77 skill points)
Autotrain is working accordingly. Please /appeal on your character to have a GM check its points.