Usually, when you use the composer toolbar, the part you can customize is highlighted.

But when you insert a blockquote, not just Blockquote but also > is highlighted. So you likely accidentally delete it.

Usually, when you use the composer toolbar, the part you can customize is highlighted.

But when you insert a blockquote, not just Blockquote but also > is highlighted. So you likely accidentally delete it.

The list item ones also highlight everything.