Validation problem over UTF-8 encoding

[diega]

My last name has the character ó in it. I have my .gitconfig with the following section

[user]
  name = Diego López León
  email = dieguitoll@gmail.com

and I uncommented the default prepare-commit-msg hook for adding signatures as follows

SOB=$(git var GIT_COMMITTER_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
git interpret-trailers --in-place --trailer "$SOB" "$COMMIT_MSG_FILE"
if test -z "$COMMIT_SOURCE"
then
  /usr/bin/perl -i.bak -pe 'print "\n" if !$first_line++' "$COMMIT_MSG_FILE"
fi

This setup generates the following commit diega/besu@6940f8f9 which doesn't validates DCO properly. On the other hand I had created on another computer with similar setup this other commit diega/besu@017d9c95 which validates just fine.

TL;DR;

[...]
From: =?UTF-8?q?Diego=20L=C3=B3pez=20Le=C3=B3n?= <dieguitoll@gmail.com>
[...]
Signed-off-by: Diego López León <dieguitoll@gmail.com>

validates. And

[...]
From: =?UTF-8?q?Diego=20Lo=CC=81pez=20Leo=CC=81n?= <dieguitoll@gmail.com>
[...]
Signed-off-by: Diego López León <dieguitoll@gmail.com>

doesn't