Ok, so looking at the notes you sent me.
Problem 1
I believe the problem is with the note that you have created and the Anki editor. Given the rather complex HTML your note has you have to be really careful of how to position the cursor to get the cloze tags to insert at the correct place (the Anki editor tries to guess where it is supposed to go). For instance, looking at a part of the HTML for your “Problem 1 Flashcard” you can see that the cloze tags bridge several HTML tags which results in strange rendering results when the cloze is hidden (end tags and start tags also become hidden) as well as how to interpret clicks as Flexible Cloze inserts a div or span tag around the cloze tag resulting in this case in invalid HTML:
<div>
<div><hr></div>
<div style="text-align: center;">
{{c8::
<span style="background-color: rgb(255, 255, 233);">
<b>X medio de quién será la comparecencia en juicio</b>
</span>
}}
</div>
<div style="text-align: center;"><br></div>
<div>
<b style="background-color: rgb(85, 85, 127);"><font color="#ffffff">23.1 LEC</font></b>
: {{c1::La comparecencia en juicio será x medio de procurador, k <b>habrá</b> de <b>SER</b> Licenciado en D, Graduado en D u otro título universitario de Grado equivalente, habilitado para <b>EJERCER</b> su profesión en el T k conozca del juicio.}}
</div><b></b>
<div></div><div><hr></div>
<div style="text-align: center;">
{{c8::
<span style="background-color: rgb(255, 255, 233);">
<b>En qué podrán comparecer los litigantes x sí mismos</b>
</span>
}}
</div>
<div style="text-align: center;"><b style="background-color: rgb(85, 85, 127);"><font color="#ffffff"><br></font></b></div>
<div>
<b style="background-color: rgb(85, 85, 127);"><font color="#ffffff">23.2 LEC</font></b>: {{c2::<font color="#108040"><b>No obstante </b></font>lo <b><font color="#1e67ff">DISPUESTO</font></b> en el <font color="#9900ff">apartado</font> anterior, ✊🏼<b>podrán</b> los litigantes <b>COMPARECER</b> x sí mismos:</div>
</div>
<blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;">
<div>
<font color="#e6e6e6" style="font-weight: bold; background-color: rgb(16, 128, 64);">1.º</font> En los juicios verbales cuya <b>determinación</b> se haya efectuado x razón de la cuantía y ésta no exceda de 2.000€, y <u>PARA</u> la petición inicial de los proc's monitorios, <u>CONFORME</u> a lo <b>
<font color="#ff2727">PREVISTO</font>
</b> en esta L (LEC).<span style="background-color: rgb(255, 255, 255);"><br></span><b><span style="background-color: rgb(16, 128, 64);">
<font color="#e6e6e6">2.º</font>
</span> </b>En los juicios universales, cuando se limite la <b>COMPARECENCIA</b> a la presentación de títulos de crédito <span style="background-color: rgb(255, 233, 229);"><u>o</u></span> D's, o para concurrir a Juntas.<span style="background-color: rgb(255, 255, 255);"><br></span><b>
<font color="#e6e6e6" style="background-color: rgb(16, 128, 64);">3.º</font>
</b>En<b> </b>los <span style="background-color: rgb(255, 222, 222);"><b>incidentes</b></span> relativos a impugnación de resoluciones en materia de AJG y cuando se soliciten medidas urgentes con anterioridad al juicio.}}
</div>
</blockquote>
For the HTML to be “correct” the cloze tags must wrap complete HTML tags (I see you have set FCZ to use span tags rather than divs):
<div>Prompt: {{c1::Answer}}</div> ⇐ OkPrompt: <div>{{c1::Answer}}</div> ⇐ OkPrompt: {{c1::<div>Answer</div>}} ⇐ OkPrompt: <div>{{c1::Answer</div>}} ⇐ Not ok because, Flexible Cloze will wrap the cloze contents in a span resulting in Prompt: <div><span id="fcz-id-1">Answer</div></span> which is invalid HTML (the span starts inside the div and ends outside it).
So as far as I can tell the issue is not with Flexible Cloze, but rather the nature of the layout of the notes you have created. If you were to use the same note with core Anki cloze you would also get incorrect HTML which would result in unpredictable rendering (it could render as you want or not). To address this you need to ensure the cloze tags are inserted at the correct place in the HTML (which is not really visible from the editor unless you open the HTML view (ctrl+shift+x) and even then the document structure needs to be such that your cloze doesn’t start inside one tag and ends in another.
Problem 2
The sample note you sent me has the same problem with the HTML as above and I am going to guess that the problem is due to the same reason: invalid HTML. Have you had the problem on any less complex notes? Where the cloze tags are not bridging HTML tags?
