adding/enabling 'SignHeaders' in v1.2.2 config causes fail 2 sign, "DKIM: The From header field MUST be signed",

i've installed

 pip show dkimpy-milter
  Name: dkimpy-milter
  Version: 1.2.2
  Summary: Domain Keys Identified Mail (DKIM) signing/verifying milter for Postfix/Sendmail.
  Home-page: https://launchpad.net/dkimpy-milter
  Author: Scott Kitterman
  Author-email: <email address hidden>
  License: UNKNOWN
  Location: /usr/local/lib/python3.8/site-packages
  Requires: pymilter, PyNaCl, Py3DNS, dkimpy, authres
  Required-by:

on

 python -V
  Python 3.8.6

 grep _NAME /etc/os-release
  PRETTY_NAME="Fedora 32 (Server Edition)"
  CPE_NAME="cpe:/o:fedoraproject:fedora:32"

as an outbound, signing milter for

 postconf mail_version
  mail_version = 3.5.7

with config,

 dkimpy-milter.conf
  ...
  #SignHeaders
  ...

outbound mail's correctly signed

 Oct 25 14:21:07 mx.example.com dkimpy-milter[36044]: mail from: <email address hidden> ('SIZE=901', 'BODY=8BITMIME')
 Oct 25 14:21:07 mx.example.com dkimpy-milter[36044]: From: test _ <email address hidden>
 Oct 25 14:21:07 mx.example.com dkimpy-milter[36044]: 4CKC9H3znqz2M: rsa-sha256 DKIM signature added (s=dkim-4914619c35e8211e d=example.net)

and verifies/passes at all test sites.

adding _any_ SignHeaders values to config, changing _only_

 dkimpy-milter.conf
  ...
- #SignHeaders
  ...

+ SignHeaders From

or

+ SignHeaders From,Sender,Reply-To,Subject,Date,Message-ID,To,Cc,MIME-Version,Content-Type,Content-Transfer-Encoding,Content-ID,Content-Description

or

+ SignHeaders From,Sender,Reply-To,Subject,Date,Message-ID,To,Cc,MIME-Version,Content-Type,Content-Transfer-Encoding,Content-ID,Content-Description,From

outbound mail -- (re)sending the same mail -- logs,

 Oct 25 14:59:32 mx.example.com dkimpy-milter[37766]: mail from: <email address hidden> ('SIZE=901', 'BODY=8BITMIME')
 Oct 25 14:59:32 mx.example.com dkimpy-milter[37766]: From: test _ <email address hidden>
 Oct 25 14:59:32 mx.example.com dkimpy-milter[37766]: DKIM: The From header field MUST be signed

and the mail's sent unsigned.