See also T317967: Opening a section link/anchor, content scrolls up itself a bit in Vector 2022

There doesn't seem to be any issue with Vector 2022, here, but with gadgets enabled on Wikidata. @Patafisik what gadgets do you have enabled on that page? It seems that certain ones are pushing down the content of the page. This sounds very much like a duplicate of T321062.

Please compare https://www.wikidata.org/wiki/Q769799#sitelinks-wikipedia
with
https://www.wikidata.org/wiki/Q769799?safemode=1#sitelinks-wikipedia

Is the latter link less jumpy?

Look like a banner is loading at the top after the initial load. When it happens again can you check if there is a banner at the top of the page?

@Jdlrobson @Lydia_Pintscher Hi, thank you for taking time to take a look at the problem. No, it is not because of a banner, the layout scroll up, not down. When a banner opened, I closed it and tried again, with the same result. But I discovered it not exactly caused by narrow screen. I repeated the experience with a friend with her account, she is a newby without gadgets, but I reset all her preferences to default just in case. The only thing different from default is Vector 2022 selected. I tried with Chrome and in Firefox. The behavior is the same, with or without safemode. What is different is the layout of Wikidata (the position of the section "Wikipedia"). The problem is when you are logged in in Wikidata with Vector 2022, or when the screen is narrow so the section "Wikipedia" is on the bottom of the page. I don't know if it should help.

Logged in in Wikipedia, logged out in Wikidata, without gadgets:

Logged in in Wikipedia and Wikidata, without gadgets:

The issue is not a visible problem on legacy Vector as the list is always at the top of the page. (See related T316797 )

My guess is that there is content causing reflows which load after the hash fragment process (which is a performance problem too). Definitely not an issue in Vector 2022 code from what I can see.