Why does the redirect add extra http?

Question

linux

Good afternoon.
On the new site, all pages with html at the end, on the old one, not all. I do a redirect I
Redirect 301 /oldpage /newpage.html
click the page in chrome and get that the page is searched for at http://http://oldpage , i.e. added for some reason extra http. I don't use http redirect at all. What it is?