PHP strip_tags在ckeditor文本区域中删除新行。 怎么阻止它？

I'm using below line to remove text formatting from ckeditor result text area for some reasons.

html_entity_decode(strip_tags($result_string_from_ckeditor),ENT_QUOTES,'utf8');

It works great except than it stripping new lines and all separate lines will be join to each other.

I tried solution in this post and used below line, but no success

html_entity_decode(strip_tags(nl2br($result_string_from_ckeditor),'<br>'),ENT_QUOTES,'utf8');

Edit: for example

ckeditor source text:

<p>This is an example</p>

<p>of problem in strip_tags</p>

Source result after using command:

<p>This is an exampleof problem in strip_tags</p>

Many thanks.