Posting YouTube links causing issue

[Hoddie]

We have a self-hosted solution. Until we upgraded to the latest patch it was possible to paste a YouTube URL into the editor and it would be converted into an embedded placeholder with thumbnail. This still appears to happen while editing the post, but when submitting, the new post does not show and the URL changes to include "&failedReply=1" at the end.

Before the latest patch, when pasting a YouTube URL, the following code would be added to the post:

<div class="ipsEmbeddedVideo">
	<div>
		<iframe allowfullscreen="" frameborder="0" height="150" id="ips_uid_6471_5" src="https://www.youtube.com/embed/Sk-_CCg9HnA?feature=oembed" width="200"></iframe>
	</div>
</div>

<p>
	&nbsp;
</p>

Since the upgrade, when pasting a YouTube URL, the following is added:

<div class="ipsEmbeddedVideo" contenteditable="false">
	<div>
		<iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="150" src="https://www.youtube.com/embed/Sk-_CCg9HnA?feature=oembed" width="200"></iframe>
	</div>
</div>

<p>
	&nbsp;
</p>

It's quite different and the change appears not to be accepted by our server.

Please help me understand how I can fix this.

[Marc]

Please check mod_security logs on your server (or maybe even securi). Its likely the request is being blocked there