How can I prevent voice to text from misspelling words, grammar and capitalization on iPhone?

I have had ongoing issues with voice to text, primarily in Messages, but it also does the same thing when I'm writing posts in other apps like Facebook. I will press the microphone button, then speak a sentence. The sentence will be transcribed correctly, with the first letter of the first word capitalized, as it should be.

Then when I tap the microphone to stop recording, it immediately switches the first letting, making it lowercase and incorrect.

I also have it where it transcribes words correctly, then as soon as I press the microphone button, it changes the words, misspells the words, or capitalizes them in really weird ways. For example, if I'm writing a sentence that includes the word "jewelry" (I'm a jewelry designer), every time it goes back and changes the word to be "Jewelry" (capitalized).

I'm spending almost more time correcting the transcriptions than inputting the words by voice. Is there a setting that I've missed? Is there a way to stop the phone from correcting my grammar, capitalization, and spelling?

[Re-Titled by Moderator]

Original Title: Voice to text transcribes correctly, then changes capitalization when microphone button is pressed to end