**<big>This is a test:** End test.</big>
Preview shows (image):
Actually shows (image for historical reference):
Actually shows (text):
This is a test: End test.
Changing it to
<big>**This is a test:** End test.</big>
as I’d meant to do shows it correctly and consistently. I’m not sure what the expected behavior of the strangely ordered markdown + HTML should be, but it should at least be consistent between the preview and the actual post.