Importing problem

I have imported content from German TV at the ARD Mediethek https://www.ardmediathek.de/ but now it is no longer working. I deleted the LingQ Chrome Extension and downloaded it again but it still does not work. I get this message.
Error: Importing failed - Unable to download JSON metadata: HTTP Error 503: Service Unavailable

What can I do to solve the problem?

Were you able to import from that source before?

Yes I worked fine until October. When I tried in December and now in January I get the same message.

I just tried to import it as well for the fun of it. Also doesnt work on my end. So its either on lingqs end or the website itself.