Doesn't look related to Vector 2022 (also in https://en.wikipedia.beta.wmflabs.org/wiki/Special:Contributions?useskin=vector and https://en.wikipedia.beta.wmflabs.org/wiki/Special:Contributions?useskin=monobook)

https://gerrit.wikimedia.org/g/mediawiki/core/+/56479ee58170d0f2a0a0e53f9bd6976a3580ad8b/includes/specials/SpecialContributions.php#838

That page doesn't exist on English Wikipedia: https://en.wikipedia.org/wiki/MediaWiki:Sp-contributions-explain

Perhaps this code has been forgotten and should be removed?

The sp-contributions-explain message was introduced by Rob Church back in 2007 (!) in 18e76e925995521b9b20dcbb6d3bfe9c555ad48e (rSVN24091) for MediaWiki 1.11 to fix T12530: Add a legend to Special:Contributions.

The newer-style question mark icon based help system (OutputPage#addHelpLink), which Special:Contributions also uses, as do many other core and extension-provided special pages these days, was introduced by @Nemo_bis in 376c0a13df05f30367b2a89c2cac7bdab22600ed for MediaWiki 1.25 (as per its @since note in the OutputPage class) to fix T45591: Link translatable help pages on mediawiki.org from the relevant special pages, actions etc..

Having both seems kinda redundant to me and it's probably better to use the icon-style help link instead, because it's the de facto standard.

It does not display on https://en.wikipedia.beta.wmflabs.org/wiki/Special:Contributions?safemode=1, so it seems to be some local customization.

In T329367#8607170, @matej_suchanek wrote:

It does not display on https://en.wikipedia.beta.wmflabs.org/wiki/Special:Contributions?safemode=1, so it seems to be some local customization.

It does. Look at the panel footer. The safemode means css for #coordinates is not loaded, which is what moves it to the top.

Checked wmf.22 and testwiki wmf.23 - the link "Help: User contributions" is not displayed on Special:Contributions page.

Change 889335 had a related patch set uploaded (by Ammarpad; author: Ammarpad):

[mediawiki/core@master] SpecialContributions: Remove duplicate help link

https://gerrit.wikimedia.org/r/889335

Change 889335 merged by jenkins-bot:

[mediawiki/core@master] SpecialContributions: Remove duplicate help link

https://gerrit.wikimedia.org/r/889335