iPad VoiceOver Siri voices speaking rate not adjusting in iPadOS 27.0

I just updated my iPad A16 (which doesn't support Apple Intelligence or the new Siri AI) to iPadOS 27.0. I am low vision blind and use VoiceOver to speak the screen. I hate the Samantha default voice, so I use the American male Siri 1 voice in VoiceOver. But now when I adjust the speaking rate, the voice stays the same default 50% speed no matter what I do. Adjusting the speed to 55% or 60% will only adjust the speed for the classic voices like Samantha, but is ineffective for any of the Siri class voices. There is a mismatch between the updated iPadOS 27 Siri voices under the "Siri" section of the iPad Settings app (which sound different now) and the older Siri voices in VoiceOver. So the older Siri voices speaking rate speed no longer functions properly, no matter what I do. This is a bug and a regression.

I have tried resetting VoiceOver settings, the issue still exists. I have tried rebooting my iPad, issue still exists. I even try adjsuting the speaking rate with the rotor, that doesn't work either. Main thing is that only the SIRI voices are affected by this speaking rate bug, not the legacy voices like Samantha or Victoria. Are the old iOS 26 Siri voices officially unsupported/deprecated by VoiceOver now in version 27? The speaking rate adjustment previously worked for the "Siri 1" voice in iPadOS 26. The only workaround that does work is changing the voice preset to faster pace, but that lacks the granularity of the speaking rate slider.

Please let me know if you are able to replicate this bug where the speaking rate for Siri voices in VoiceOver fails to honor the slider setting.