Looks the same in source mode and live preview. The first line appears to be 24 spaces indented, but when I try to type in the spaces manually or use Tab for another paragraph, I can’t seem to reproduce the centering. Only if I paste it again can I achieve this centering.
There are no HTML tags involved, either. And in edit mode, the paragraphs can be collapsed.
Even though they look like spaces they are probably Nonbreaking Spaces which is a different character so Obsidian doesn’t treat them like normal spaces.
Try this, copy the code below into a text file
Hi
<br>
Hello
name the text file “nbsp.html” or anthing else that ends in an extension .html
open it in your browser. It should look like this in the web browser:
copy from the browser to an obsidian note
the is how nonbreaking spaces are represented in HTML.