I can't find Barnard's variable in M3 (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NAME+Barnard+Variable+in…).
There is nothing to find (that fits the description) very close to position 13 42 11.734 +28 22 13.71 in VSX
What am I missing?
This is because we don't systematically include globular cluster variables in VSX.
In the past the decision was made because their positions weren't accurate enough and those variables would cluster any chart if added altogether.
Eventually we will likely include them. As for now, we are adding them individually if there is interest in study any of them.
I have added this one to VSX: