When I create a callout with a custom title, Obsidian changes the case of the first letters of all words (except the first word) to lower case. For instance, when I write
> [!Hi There Guys 'n Gals]
then Obsidian shows
Hi there guys 'n gals
in live preview mode as well as in reading mode.
Obsidian should leave the text that I type as is, shouldn’t it?
Just tested this in about 10 different themes and it does it in all of them. Only the first letter of the first word is capitalized (note that it is capitalized even if you type a lowercase letter).
Edit:
I just copy/pasted your example without looking closer at it. Silly me.
Please resubmit this bug report and make sure that: 1) you follow the bug report template, 2) you use the default theme (no css) and 3) there are no third-party plugins enabled (You can use the sandbox vault for 2 and 3).