"During the day I do not want to walk."
Translation:Interdiu ambulare non volo.
He might mean Plautus' Amphytruo Act 1, Scene 1, in which Sosia is being bullied by Mercurius: Nōn ēdepol volō profectō "I do not, by Pollux, want [a beating] of course." In this case, I think that the expletive ēdepol causes the nōn to survive being in the same sentence as volō. I do not think that it is enough to prove the existence of an independent nōn volō even by Plautine times, let alone later ones, but it is true that this sentence exists.
Yes, something seems to be going on with the repeated profectō (five times in 3 lines!), and the separation of nōn and volō by ēdepol seems to be key.
Since they say nōn vīs , nōn vult , nōn vultis in the same paradigm, perhaps it's not surprising if a nōn [extraneous word] volō can be produced (for special emphasis?), but it's certainly not common, in my experience.
But nōlō really doesn't come from "nōn" + "volō."
It looks as though the PHI will come up with passages that have nōn and volō in the same sentence or clause; if you look carefully, you'll see that the nōn is negating some other word (not the "volō"). Maybe you can point to the examples you're judging from?
There's "nōn vīs" and "nōn vult" and "nōn vultis," but otherwise it's nōlō, nōlumus, nōlunt.