Hey there, and welcome to Apple Support Communities bdhammel,
We can certainly understand your concern and can help provide some insight.
We recommend checking out these steps for more information on how to check spelling and grammar on your Mac and see if it matches up with your procedures.
" Check spelling and grammar on Mac
In many macOS apps, spelling is checked while you type, and mistakes are automatically corrected. You can turn off these features, and use other options while typing emails, messages, or documents.
Siri: Say something like: “How do you spell [word]?” Learn how to ask Siri.
Use autocorrection
When your spelling is checked, misspelled words are underlined in red, and suggested corrections are shown.
- On your Mac, choose Apple menu
> System Settings, then click Keyboard 
in the sidebar. (You may need to scroll down.) - Go to Text Input on the right, then click Edit.
- Turn on “Correct spelling automatically,” then click Done.
Note: To have the first word of a sentence and proper nouns (such as California or Tim) automatically capitalized as you type, turn on “Capitalize words automatically.”
4. In an app, type your content.
5. 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 settings 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.
Check spelling and grammar
In an app on your Mac, do any of the following:
- Check spelling: Choose Edit > Spelling and Grammar > Check Document Now. The first error is highlighted. To show the next error, press Command-Semicolon (;). To see suggested spellings for a word, Control-click it.
- Check grammar: Choose Edit > Spelling and Grammar > Check Grammar With Spelling (a checkmark shows it’s on). Grammar errors are underlined in green. Move the pointer over an underlined word to see a description of the problem.
- Note: Grammar-checking is not available for every region, country, or language. See the macOS Feature Availability webpage.
- Ignore misspellings: Control-click a word, then choose Ignore Spelling. The word is ignored if it occurs again in the document (it is highlighted in other documents).
- Add words to the spelling dictionary: Control-click a word, then choose Learn Spelling. The word won’t be flagged as misspelled in any document.
- Remove a word from the spelling dictionary: Control-click a word, then choose Unlearn Spelling.
If you’re checking a long document, it may be easier to use the Spelling and Grammar window. Choose Edit > Spelling and Grammar > Show Spelling and Grammar. "
For additional information, check out this link: Check spelling and grammar on Mac - Apple Support
If you have followed all these steps and the issue still remains, then the next step would be to start your system in safe mode and see if it happens there. Check out this link on how to enter safe mode:
Start up your Mac in safe mode - Apple Support
These steps will help ensure your device is working with ease when performing the task and help isolate the issue.
Kindest regards!
