Join on document key returns incorrect results

SELECT *
FROM `travel-sample` r
JOIN `travel-sample` a
ON r.airlineid = META(a).id
WHERE a.country = "United States"
limit 10

The above query result includes airlines from country other than United States. Only primary on bucket is used in the plan.

Build: Enterprise Edition 7.0.0 build 3613

Not reproducible in Enterprise Edition 6.6.0 build 7909