Forced line break leads to broken editor on load

[Drivingralle]

If a forced line break <br> is part of a tag content that has a binding the following notices show up:

Warning: DOMDocument::loadXML(): Opening and ending tag mismatch: br line 2 and h2 in Entity, line: 2 in /wp-content/plugins/create-content-model/includes/runtime/class-content-model-html-manipulator.php on line 28

Warning: DOMDocument::loadXML(): Premature end of data in tag h2 line 2 in Entity, line: 3 in /wp-content/plugins/create-content-model/includes/runtime/class-content-model-html-manipulator.php on line 28

On reloading the content type the tag is missing and block is broken.

The XML parsing has trouble with the <br> tag. If the tag is changed to <br /> the problem is gone.
In my client project I replace the tag on save. Doesn't feels like a good solution.

[Drivingralle]

A similar error happens if the content of a block with binding is filled with a string containing a forced line break.

Warning: DOMDocumentFragment::appendXML(): Entity: line 6: parser error : Entity 'nbsp' not defined in /wp-content/plugins/create-content-model/includes/runtime/class-content-model-html-manipulator.php on line 142

Sanitizing the post meta value is very tricky