https://www.wikidata.org/w/rest.php/wikibase/v1/suggest/items?q=Sandbox&language=en&offset=10001 returns []

whereas Item search https://www.wikidata.org/w/rest.php/wikibase/v1/search/items?q=Sandbox&language=en&offset=10001 returns a 500 error.

1. continue/offset in wbsearchentities has a 10000 limit
2. T390694 and T389013 say a 400 response should be returned.