Bug Report: Importing removes slashes in file attachment links

I once had a blog on blog.werunskenntderkenntuns.de. I’ve exported the xml of all posts and backed up the wordpress uploads folder. I’ve imported the xml on the new wordpress site without the subdomain werunskenntderkenntuns.de.

I’ve also uploaded all pictures to the correct folder. The issue is, that all posts point to an invalid image url. The slash before /wp-content is missing:

wrong:
https://werunskenntderkenntuns.dewp-content/uploads/2019/06/img_20190622.jpg

correct:
https://werunskenntderkenntuns.de/wp-content/uploads/2019/06/img_20190622.jpg

Here is an excerpt of the exported xml:

xml
		<title>img_20190105.jpg</title>
		<link>https://blog.werunskenntderkenntuns.de/2018/12/19/danzer-party-04-01-2019/img_20190105-jpg/</link>
		<pubDate>Mon, 14 Jan 2019 09:50:49 +0000</pubDate>
		<dc:creator><![CDATA[nicohood]]></dc:creator>
		<guid isPermaLink="false">https://blog.werunskenntderkenntuns.de/wp-content/uploads/2019/01/img_20190105.jpg</guid>
		<description></description>
		<content:encoded><![CDATA[]]></content:encoded>
		<excerpt:encoded><![CDATA[]]></excerpt:encoded>
		<wp:post_id>1142</wp:post_id>
		<wp:post_date><![CDATA[2019-01-14 10:50:49]]></wp:post_date>
		<wp:post_date_gmt><![CDATA[2019-01-14 09:50:49]]></wp:post_date_gmt>
		<wp:comment_status><![CDATA[open]]></wp:comment_status>
		<wp:ping_status><![CDATA[closed]]></wp:ping_status>
		<wp:post_name><![CDATA[img_20190105-jpg]]></wp:post_name>
		<wp:status><![CDATA[inherit]]></wp:status>
		<wp:post_parent>1068</wp:post_parent>
		<wp:menu_order>0</wp:menu_order>
		<wp:post_type><![CDATA[attachment]]></wp:post_type>
		<wp:post_password><![CDATA[]]></wp:post_password>
		<wp:is_sticky>0</wp:is_sticky>
						<wp:attachment_url><![CDATA[https://blog.werunskenntderkenntuns.de/wp-content/uploads/2019/01/img_20190105.jpg]]></wp:attachment_url>
											<wp:postmeta>

Note: I’ve modofied the image name, as I dont want anyone to access the real pictures.