Pardon my ignorance. What is a PVA glue?
PolyVinylAcetate. Essentially white and yellow carpenter/woodworking glues.
Not quite. There's also aliphatic resin emulsion, that is the yellow glue
This detail might be where the confusion lies then. Perhaps the aliphatics stick better to a cured line?
Some woodworking sites mention TB as a PVA which does not seem to be the case.
I incorrectly assumed yellow glue was just the same as white glue with an additive.