(Frrely translated by @Josve05a using Google Translate, from https://sv.wikipedia.org/wiki/Wikipedia:Wikipediafr%C3%A5gor#F.C3.B6rsvunnen_logga)

Since a few weeks back, the Wikipedia logo at the top left missing for me at smaller screens (13.3 "), on the large screen (17") however, it looks as usual. If I zoom out and view the page in less than 100% the logo pops up. Now on the edit-a-thon recently in Gothenburg, I discover that I am not alone in experiencing this. It just seems to be a problem on sv.wp and that is regardless of being logged in or not. Someone who knows what might have happened?

I see the same problem with the logo "disappearing" in a specific "zoom ranges" no matter if I use Microsoft Edge or Mozilla Firefox browser. When the elements of the code represent the <div id="p-logo" role="banner"></div> is less than 240 × 240 or larger than 300 × 300 the logo is visable as it should, but for sizes between (and including) 240 × 240 and 300 × 300, everything you see is an empty white box. Could possibly be due to the "renderings" of the login screen for these sizes have failed and the unsuccessful outcome lies in a cache somewhere on the way and will not be updated. Someone would then need to clear the cache. But this is only a guess.

The above-mentioned "div" contains the following code: <a class="mw-wiki-logo" href="https://sv.wikipedia.org/wiki/Portal:Huvudsida" title="Besök huvudsidan"></a>Maybe it's something with the class "mw-wiki-logo" which needs to be fixed.