Error evaluating filter. - cause: FROM in correlated subquery must have USE KEYS

I am using Couchbase Server Version: 4.6.3-4136 Enterprise Edition (build-4136),
and my N1QL s following:

SELECT f.f1
  FROM default f
 WHERE f.f2 IN (SELECT RAW s.f3 
                  FROM default s 
                   LET k1 = (SELECT RAW l.ff FROM default USE KEYS "key1" ),
                       k2 = (SELECT RAW l.kk FROM default USE KEYS "key1" )
                 WHERE s.f4 IN k1 AND s.f5 == k2[0])

the error shows

[
  {
    "code": 5010,
    "msg": "Error evaluating filter. - cause: FROM in correlated subquery must have USE KEYS clause: FROM default."
  }
]

is there any other way to get the same result with the same logic?

Try this

SELECT f.f1
  FROM default f
 WHERE f.f2 IN (SELECT RAW s.f3
                  FROM default s
                 WHERE s.f4 IN (SELECT RAW l.ff FROM default USE KEYS "key1") AND s.f5 == (SELECT RAW l.kk FROM default  USE KEYS "key1" )[0]);

Opened MB-26468

it works. thank you.