When a user moves a page from the main space to a userspace sandbox the move does not reflect in the Wikidata item (Wikidata site link should be removed automatically). Examples,
- [[ https://hy.wikipedia.org/wiki/%D5%83%D5%A1%D5%B6%D5%A1%D5%BA%D5%A1%D6%80%D5%B0_%D5%A4%D5%A5%D5%BA%D5%AB_%D5%BF%D5%B8%D6%82%D5%B6_(%D6%86%D5%AB%D5%AC%D5%B4,_2019) | This move is done with a gadget (via API)]] ([[ https://www.wikidata.org/wiki/Q57314401 | check Wikidata ]])
- [[ https://hy.wikipedia.org/w/index.php?title=%D5%8D%D5%A1%D5%B0%D5%B4%D5%A1%D5%B6_(%D5%B4%D5%A1%D5%A9%D5%A5%D5%B4%D5%A1%D5%BF%D5%AB%D5%AF%D5%A1) | This move is done "with a hand" but the result is the same ]] ([[ https://www.wikidata.org/wiki/Q177239 | check Wikidata ]])
As a result, many site links in Wikidata does not exist.
P.S. Is there an easy way to find all such items?