Parental Controls approval process fails authentication for one parent but not the other

I am having a significant problem authorizing purchases through Parental Controls.

1. My son requested approval to purchase a song through the iTunes Store on a M2 Mac Mini running 27.0. Regardless of whether I tried to approve it via my User account on the same Mac, or via my iPhone 16 Pro (on 27.0), authentication failed.
2. My other son requested approval to get the free iMovie app from the App Store on his iPhone 12 Mini running iOS 27. I received the request on my phone and attempted to approve the request, and it gave me an authentication error.

My wife was able to respond to the same request on her 16e (27.0) and successfully approve the iMovie download. (I did not try using her phone to approve the song purchase). It appears to be somehow connected to my Apple Account, since it fails on both Mac and iPhone approval attempts for me personally, but not for my wife.

How do I fix this?!