The liquid hive part only happens if the haircut rule hits (too much hbd per hive because of a low price) and so far the hive price has sustained high enough for it to not happen.
hive price below 1$
It's more complex than that but yes it's a calculation of ratio between the total hive marketcap and the total hbd marketcap. Double check this (google hbd haircut) but I remember it being something like 20%, so if the hbd marketcap is at 20% of hive's then there will be no HBD printed anymore.