List of steps to reproduce (step by step, including full links if applicable):

• Open https://query.wikidata.org/querybuilder/
• Select "instance of" (P31) as property
• Make sure "Include related values in the search (recommended)" is checked
• Select "Regardless of value"; "Include related values in the search (recommended)" is now disabled and can not be unchecked
• Click "Run query"

What happens?:
This query is executed, which will time out:

SELECT DISTINCT ?item ?itemLabel WHERE {
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE]". }
  {
    SELECT DISTINCT ?item WHERE {
      ?item p:P31 ?statement0.
      ?statement0 (ps:P31/(wdt:P279*)) _:anyValueP31.
    }
    LIMIT 100
  }
}

What should have happened instead?:
The query should be intepreted as if "Include related values" is not checked:

SELECT DISTINCT ?item ?itemLabel WHERE {
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE]". }
  {
    SELECT DISTINCT ?item WHERE {
      ?item p:P31 ?statement0.
      ?statement0 (ps:P31) _:anyValueP31.
    }
    LIMIT 100
  }
}

In addition, do not include the "subclass" field in JSON.

Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc: