Markdown in blockquotes in a reply email does not convert to HTML

Markdown in blockquote sections in a new email is correctly rendered to HTML. In an email reply it is not converted to HTML.

In the MailMate editor the following text:

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus vitae risus vitae lorem iaculis placerat.

> Aliquam sit amet felis. Etiam [congue](#). Donec **risus** risus, pretium ac, tincidunt eu, tempor eu, quam.

Morbi **blandit** [mollis](#) magna.

… should convert [congue](#) and [mollis](#) into HTML links, and **risus** and **blandit** into bold text.

If the email is a new email (the MailMate editor is launched from the compose button) it is converted as it should be in both places:

1. It renders as rich text in the MailMate HTML preview

2. It's converted to HTML in the .eml stored by MailMate and the sent email stored by Gmail (with some minor changes to line wrapping in its quoted-printable encoding):

<p dir="auto">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus vitae risus vitae lorem iaculis placerat.</p>

<blockquote style="border-left:2px solid #777;color:#777;margin:0 0 5px;padding-left:5px">
<p dir="auto">Aliquam sit amet felis. Etiam <a href="#m_2827023153906087262_" style="color:#777">congue</a>. Donec <strong>risus</strong> risus, pretium ac, tincidunt eu, tempor eu, quam.</p>
</blockquote>

<p dir="auto">Morbi <strong>blandit</strong> <a href="#m_2827023153906087262_" style="color:#3983c4">mollis</a> magna.</p>

If the email is a reply to an existing email (the MailMate editor is launched from the reply button) it does not convert the markdown inside the blockquote (though it does convert the markdown in the un-blockquoted section below the blockquoted section), instead showing the unconverted markdown in a blockquote, but otherwise leaving markdown as plain text.

1. It renders as plain text (unconverted markdown) in the MailMate HTML preview

2. It is not converted to HTML in the .eml stored by MailMate and the sent email stored by Gmail:

<div style="white-space:normal">
<p dir="auto">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus vitae risus vitae lorem iaculis placerat.</p>

</div>
<div style="white-space:normal"><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">Aliquam sit amet felis. Etiam [congue](#). Donec **risus** risus, pretium ac, tincidunt eu, tempor eu, quam.</p>
</blockquote></div>
<div style="white-space:normal">

<p dir="auto">Morbi <strong>blandit</strong> <a href="#" style="color:#3983C4">mollis</a> magna.</p>

</div>

(Minor: Note that the second HTML block above is missing a closing div. MailMate wraps that div around my sig and the quoted text below it (which I have not included here). That seems wrong - a div started in the middle of my reply should close before my sig.)

Mailmate 1.13.1 (5671) on macOS 10.15.1, sending via and replying to Gmail emails.