I am using TinyMCE in a post form with a textarea.
Many texts are stored in a database and may contain
tags, such as:

<p>line one<br />line two</p>

When I load such a text into the textarea, the text is still complete.
But after posting the form, the
tag is gone.

In the database I can see that the original was changed to

<p>line oneline two</p>

I also tried

remove_trailing_brs: false,

but the br-tags are still stripped.