Hello 2010JD,
It seems like you want to stop words from being automatically capitalized, or undo that specific autocorrection, is that right? If so, please check out this link, which outlines how to manage that setting and adjust autocorrections, which may help: Check spelling and grammar on Mac
Use autocorrection
When your spelling is checked, misspelled words are underlined in red, and suggested corrections are shown.
1. On your Mac, choose Apple menu
> System Preferences, click Keyboard
, then click Text.
2. Select the “Correct spelling automatically” checkbox.
3. In an app, type your content.
4. As misspelled words are detected, do one of the following:
• Accept suggestions: If there’s only one suggestion, just keep typing to have the word autocorrected. If two or more suggestions are shown, choose one.
• Ignore suggestions: Press Esc, then continue typing.
• Undo autocorrections: An automatically corrected word is briefly underlined in blue. To revert to your original spelling, put the insertion point after the word to show your original spelling, then choose your spelling. You can also Control-click the word to show your spelling, then choose it.
To turn off autocorrection for a specific app, open the app, then choose Edit > Spelling and Grammar > Correct Spelling Automatically (it’s off when a checkmark isn’t shown).
If an app’s Edit menu doesn’t include a spelling or grammar command, check its preferences or menus to see if it has its own spell checker.
While typing, you can display a list of suggested words by pressing F5 (you may need to also press the Fn key, depending on your Mac model). If your Mac has a Touch Bar, you can set an option to show typing suggestions in the Touch Bar.
Note: To have the first word of a sentence and proper nouns (such as California or Tim) automatically capitalized as you type, select the “Capitalize words automatically” checkbox in the Text pane of Keyboard preferences.
If you need additional assistance, please contact Apple Support for assistance. You might be able to reach them here: Contact Apple Support
Thanks!