If you're mixing FX-2 and can't get the glycin to dissolve
( which usually only takes time )
add a little bit of the 7 1/2 grams of P Carb destined for the B bath.
Raising the pH a little will do the trick, with no ill effects.
FX2 is so easy to make up ( in small quantity ) as a single solution that I make it up when I need it, and don't worry over the 2 bath.
As a single bath, add the Carbonate last, a little at a time,
and the glycin dissolves just like ( SNAP ! that !
.