HomePod Recognise my voice greyed out

[ryantbfh]

Mine is fine. But I cannot turn on ‘recognise my voice’ for my mum who is in the home group. The option is greyed out. She has find my iPhone, hey Siri, location for HomeKit on etc. Everything I could find that people said to double check, I have done.
IOS 14.2. I’m stumped for ideas ?‍♂️

 

[dotme]

Under the "Find My" section of her iPhone "Settings -> Apple ID", "My Location" should be set to "This Device" and "Share My Location" should be on. (You'll see fine print under that toggle that says it's required to make personal requests using Siri on HomePod). I gather from your post you checked this but maybe a restart on her iPhone, or have her sign out of iCloud and back in, might kick things in?