Wordpress blockquote removes `<br>` tag

So I have a quote in my page template and I would like to give the user the opportunity to add line breaks whenever they desire to do so.

I wanted the blockquote to have an extra p tag inside the blockquote tag so I could style it better.

The problem I'm having now is that the br / tags are being removed. While using the wpautop() function they should stay.

Here is what I did:

$matched = preg_match("~(?=blockquote)([\s\S]+?)(?=/blockquote)~",
wpautop($child-post_content), $found); // find the quote in the content with regEx

$found = current($found);
$replace   = "blockquotep".$found."/p/blockquote";// add the p tag
$newphrase = str_replace($found, $replace, $found);

$clearQuote = preg_replace("~blockquote([\s\S]+?)/blockquote~", '', 
wpautop($child-post_content, true)); // use wpautop to keep the p tag

Can anyone see why the br tag is being removed or do I need to add something else?

I came to realize that I don't think it has something to do with the wpautop() function.

The variable I use it in is used to filter it out of the_content(). So $clearQuote uses the found quote and deletes it from the_content() where $quoteFound uses the found value and doesn't use wpautop(). So it must be something else.

I added the wpautop() function to the $matched variable so it would add a p tag to where the user break the line. This way there isn't really a line break but the output is the same.