Sounds like you got it all sorted
But just to follow up ... the stock knob has gobs of RED threadlocker, which Loctite refers to as "high strength permanent". This is why the knob is so damn hard to remove. The blue threadlocker is "medium strength removable".
Loctite Threadlocker Colors. Apply a small line of it across several threads of the shifter assembly (easier than trying to apply it inside the knob).