Bold/italic within word doesn't work

[friggog]

Description

Including bold (**) or italic (*) within words currently results in asterisks appearing in the HTML with a link, e.g. **b**o**l**d or *i*tal*i*c

The first will give:
<a href="#id1"><span class="problematic" id="id1">**</span></a>b**o<a href="#id1"><span class="problematic" id="id2">**</span></a>l**d

Working fine when wrapping a full word e.g. **bold** or *italic*

Details

• OS: Windows/Linux
• Python version: 3.9
• Project version: 0.5.3
• Can you repro on main?
• Can you repro in a clean virtualenv?

[friggog]

The same is true for inline raw HTML - e.g. <b>B</b>o<b>l</b>d fails while <b>Bold</b> succeeds. This isn't limited to <b> tags - but applies for any HTML e.g. <span>