Mac Capitalizing The Word "Kindly"

Looks like this question has been asked before, but still no answer:

Whenever I type "Kindly" -- like I did just now-- it automatically gets capitalized. If I go back and correct it to "kindly" it remains lower case. This happens across all apps.

I have checked in all of the auto correct or text replacement I can find, and I can assure you that there are no options specifically pertaining to the word Kindly.

Again: I looked in system preferences, and although I do have a few autocorrect options, "Kindly" is not one of them.

Finally, if I highlight the word, there is no "unlearn" option. The problem seems to be at a deeper level. Please help!