When ever a field has a tooltip. the reprensentation of it breaks in the backend registering detailed view.
For example
https://www.inseln-der-macht.de/administrator/index.php?option=com_dtregister&task=edit&controller=user&cid[]=3260
<div class="control-label"><label class=" fieldlabel" data-content="<span class=" hastooltip"="" title="Wann wurdest du geboren"><img src="/media/system/images/tooltip.png" alt="1">" data-original-title="Geburtsdatum: <span class="dtrequired">* </span> ">Geburtsdatum: <span class="dtrequired">* </span> </label></div>
is shown as the following where (i) is the tooltip icon:
(i) " data-original-title="Geburtsdatum: ">Geburtsdatum:
I would expect that I see here just:
(i) Geburtsdatum:
Not so nice, but also not so urgent. can be fixed with one of the next releases.