When you changed the sear engagement angle, the rest of the components followed along. (discussion in the Triggers topic where we talk about some guy who decided to* fine tune* a factory trigger
...again, Pavise on point
My guess is now the nut locks in a position where it's slightly rotated forward - this would tempt the string to sit a little higher on the teeth with all the following outcomes.
If that is so, then I'm with Gnome on refiling the teeth so that they *hook* the string.
In fact, I would go a little further and round off the tips and edges of the teeth while at it.(third nut in the picture)
Anyway, that's my guess and the easier solution...another being to relocate the tickler axel following the the extended radius of the nut till the teeth are angled a little back.
PS: Prod angle...I never really even cared for prod angle - just as long
as the string touches the stock it's good. Having some string pressure
on the stock is actually there to work in your favor and the age old
formula for that is:
~ Center of the tips should be 1/2 thickness of the string lower than the surface of the track
(at least with thin modern strings