Impossible to access an attribute ("function") on a null variable.
{% set accordionItemContent %}
<div class="row">
<div class="col-12 col-md-6">
<p>
{% if member.function.value() %}{{ member.function }}<br />{% endif %}
{% if member.officeHours.split()|length %}Bürozeiten: {{ helpers().formatOfficeHours(member.officeHours.split()) }}<br />{% endif %}
{% if member.phone.value() %}{{ layout.phone(member.phone) }}<br />{% endif %}
{% if member.email.value() %}{{ layout.email(member.email) }}<br />{% endif %}
{% if member.website.value() %}{{ layout.url(member.website) }}<br />{% endif %}
</p>
</div>