inline images not showing

[pverkind]

I want to use a forumng on Moodle for a programming class. Students should be able to post screenshots.
The editor allows pasting the screenshot in the post and it's shown in the preview:

But the pasted image is not shown in the post once it is posted.

(NB: the link to the image in the upper right corner is from attaching the image, not pasting it)

The image is not in the page source code either:

<div class="forumng-message" id="yui_3_17_2_1_1739082380678_279"><p>I'm trying to print a variable in FutureCoder (lesson: https://futurecoder.io/course/#AddingStrings), but I get a NameError:</p>
<p>Code:&nbsp;</p>
<p id="yui_3_17_2_1_1739082380678_298"><span>&gt;&gt;&gt; </span><span id="yui_3_17_2_1_1739082380678_297">message = "Hello World!" </span></p>
<p><span>&gt;&gt;&gt; </span><span>print(mesage) </span></p>
<div class="tracebacks-container" id="yui_3_17_2_1_1739082380678_278">
<div class="traceback"><span class="traceback-exception"><span>Output:&nbsp;</span></span></div>
<div class="traceback" id="yui_3_17_2_1_1739082380678_284">&nbsp;</div>
<div class="traceback" id="yui_3_17_2_1_1739082380678_277"><span class="traceback-exception" id="yui_3_17_2_1_1739082380678_276"><span>NameError:&nbsp;</span>name 'mesage' is not defined</span></div>
<div class="traceback">
<div class="markdown-body truncated">&nbsp;</div>
<div class="markdown-body truncated">&nbsp;</div>
<div class="markdown-body truncated">&nbsp;</div>
</div>
</div></div>

When pressing the "Edit" button, the image is still there.