When using labels on chests:

• Disappears after leaving a loaded chunk via ftbchunks. Could be the same with non-claimed chunks as well.
• Applies to iron chests mod, unsure if it conflicts with each other or not
• Haven't tested this with regular chests or better chests mod, but assume it may be the same problem.
• Another small issue is the lock on chests from iron chests mod comes out of the label, basically you have an area that obstructs the view of the label.

Update: Problem occurs when you use a waystone somewhere and come back is when it disappears.