Case closed, issue resolved.
Root cause = 2nd pawl (lower and hidden from view), was not
fully pivoting, where the upper (and viewable) was free to fully pivot.
Solution used = While lube was initially used, and a heat gun for warming dried grease, the placement of the brifter FACE DOWN overnight, allowing a further migration of lubricant along with an additional heat gun cycle (warm to the touch, not hot) freed the pawl from its unwelcomed hold on the pawl shaft.
Thanks all for their responses.
