You may be right.
I cited a 2001 reference from the Institute of Physics.
Two of your quotes seem to be upper limits, not lower limits:
1. "A neutron star is less than 3.2 solar masses", Degani, Meir H. Astronomy Made Simple. New York: Doubleday, 1976: 100.
"Such a neutron star was less than 3.2 solar masses", Asimov, Isaac. Guide to Earth and Space. New York: Fawcett Crest, 1991: 228.
With kind regards,