2009 ram 1500 quad cab with the 5.7 hemi

Pulled into a parking spot today (or tried to) and completely forgot i was in 4wd🙄 bucked once per the usual, doing its “4wd tight turn” thing, but had an abnormally loud clunk, louder than the usual “please dont turn that tight in 4wd” clunk... didnt really think anything of it. Couldnt make my turn, put it in 2wd, and finished parking. Later on, i was backing up to my trailer in the snow on a slight incline, so i put it in 4wd, would not engauge. The light on the selector **** comes on indicating that it is engauged, but its deffinately not. No grinding (indicating splines from the stub shaft are steipped), no other noises.

From my research so far, seems like the two most common issues are a) vacuum leak going to the actuator (passenger side on my truck) or b) the actuator actually going bad. There was also something i read that involved a system update/programming that needs to be done? If this applies here, can someone explain that a bit?

As a side note, i recently put in a new stub axle, axle shaft seal, and cv axle on the passenger side. Could it maybe be that i got a faulty part and it has already failed?

Thank you for your help, and sorry for the long read