Take the following minimal example. The numbering of the list restarts to 1 in slide 2, when I wanted that the list of slide 2 started with 2. I tried, after intensive Google search, a suggestion given at

An addition:

## slide 4

<ol start="3">
3. Sed ut perspiciatis unde omnis iste natus error... <br>
<p style="margin-left: 25px;"> &#9675;(or &#9702;) sub-item </p>
4. Nemo enim ipsam voluptatem quia voluptas sit...
</ol>