Siri activates when you press the side or Home button, but doesn't activate when you say "Hey Siri,"
Siri activates when you press the side or Home button, but doesn't activate when you say "Hey Siri,"
iPhone 11, iOS 16
Seems you may want to check your Siri settings:
Apple Support's article: Use Siri on iPhone – Apple Support
says:
" go to Settings > Siri & Search:
If you want to activate Siri with your voice: Turn on Listen for “Hey Siri.”