Tearing my hair out trying to get FaceTime working on a MacBook Pro (15-inch, 2016)

I've set up a half-dozen Macs using OCLP, and I've never had any issues until now.

A elderly lady who tutors elementary school students bought this used Mac specifically to use FaceTime to tutor students. Problem is that Monterey is the highest OS supported by Apple, and apparently the FaceTime server-side architecture changed in such a way that Monterey can no longer make FaceTime calls.

(Strangely, my 2019 MBP with Monterey can make FaceTime calls, but everything I've read online suggests that's not possible.)

So if Monterey won't work, I can use OCLP to install something newer. I wipe her drive, install OCLP, install Monterey, and go through the new user setup. And it freezes at the "Enable Location Services" Screen.

I try again, but whether I click that checkbox or leave it unchecked, the process locks up.

If I force a reboot, it does take me to a login screen, even though I never finished the setup process. But after logging in, if I try and do something that requires a password, like creating a second user account, the password gets rejected.

I've read that booting to recovery and using Reset Password might fix this, but apparently no recovery partition got created.

I'm at wits end. Should I install Monterey first, then OCLP, then Monterey?

Should I try Ventura instead? Or Sequoia?

Please help!