Siri has two different quality voices in ios 15.1

I recently updated my iPhone 11 (128 gb) to iOS 15.1 when it came out. The only major issue I'm noticing is that Siri's voice responses will play back as normal, but when I ask for notifications to be read aloud to me, the irish female voice will be the one that happens when your phone runs low on space... but I still have 83.11 GB of space left on my phone.

I have tried using both the UK and Australian Female Siri voices, and they are just a lower quality version of siri's voice.

The real problem here is that there's probably a bug in iOS 15.1 that messed up siri, but it doesn't explain why the Female Irish Siri sounds like she's either dropped several octaves, or has a speech impediment. Why has that occurred since iOS 12 (on my 16 gb iphone 6), and why is it happening now?

Is it truly a bug in iOS 15.1 that is causing siri to assume that I'm low on space? I tried to force a download of the voice files in the settings, but it wouldn't re download the voice. any suggestions? it's driving me and my parents crazy.