"Hey Siri, read text" requires me to unlock my cell phone

I just upgraded to a new iPhone 12. It is running the same IOS as my previous phone, 15.5. What I use Siri most for is reading my text messages to me while I am driving. But now it says I need to unlock my phone first. I can't! I'm driving! That's why I'm using Siri! I see on here that this may be bug or it may be a security enhancement. I do have Allow Access When Locked turned on for Siri in my settings. So is it a bug that will be fixed? Or am I stuck with basically not being able to use Siri? Because, really, if I could unlock the phone, that would mean I was parked, and I could also read my messages. Thank you!