The main MediaWiki logo used on the Vector 2022 needs a tweak to the right leg of the 'M' to make the line straight, as I can see a slight gradient when one is not needed. See: File:MediaWiki wordmark in Vector 2022 with gradient.png
Topic on Project:Village Pump
I think that's a rendering artefact of your browser? That's a plain SVG file (mediawikiwiki-wordmark.svg) which your browser is rendering oddly, perhaps?
The SVG appears oddly on Firefox, but not on Chrome, but the SVG itself is poorly drawn in the first place.
The current SVG file dates from https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/668241 when it was provided (as a reduced copy of File:MediaWiki-2020-wordmark.svg which is just word->path of the site name) as part of the switch to the new logo; before that we just fell back to the browser printing the site name in text. I'm not sure I see you think needs fixing?