ACF Link array in W4 List

Hi,

I am trying to display a a list of information that is stored in custom fields in a custom post type on my page. Most of it is working as intended using this template:

<ul class="list-unstyled">
[groups]
<li><h5>[group_title]</h5>
<ul>
[posts]
<li>
[post_date format="d.m.Y"] [post_meta key='medium']: <a href="[post_meta key='lenke']">[post_title]</a>
</li>
[/posts]
</ul>
<br />
</li>
[/groups]
</ul>

The problem is that the links are shown as arrays, which gives rather bad links, for example:
https://lmsdln.no/media/Kan%20det%20v%C3%A6re%20at%20de%20rett%20og%20slett%20ikke%20tror?,%20https://www.bt.no/btmeninger/debatt/i/kRVg0v/kan-det-vaere-at-de-rett-og-slett-ikke-tror,%20_blank

How do I split the array when creating the list?

The page I need help with: [log in to see the link]