Help: question about MM JP neck

I need some advice about Music Man guitar.
I have a project to buy a new Music Man (JP BFR) but I’m worried about potential issue with the neck (curved). My bassist (live near Paris in tempered climate) who has a bass Sterling alerted me because the neck was curved for no apparent reason about a year ago. He owns the bass in the same room of his house for about 5 years and had never a problem before. Now the bass is unplayable, he can not put the right neck with the trussroad 🙁
I search on internet and found similar problems on other Music Man and now I am reserved on the purchase of this very expensive guitar….
Your advice are welcome…

Arno