Array merge has different result than jsonata.org

[sedlacl]

Try https://try.jsonata.org/HqTHjfPYP:
( $append([],10) )

result should be:
[ 10 ]

but it is (version 1.8.6 of JSONata4Java)
10

[sedlacl]

Second example https://try.jsonata.org/8O5qky_my:
( $data:=[ { "key": "A", "v": 1 }, { "key": "B", "v": 2 }, { "key": "B", "v": 3 } ]; $data{key:$[].v} )
result should be:
{ "A": [ 1 ], "B": [ 2, 3 ] }
but it is (version 1.8.6 of JSONata4Java):
{ "A": 1, "B": [ 2, 3 ] }

[sedlacl]

Third example (without group by) https://try.jsonata.org/37HFPJFKc :
( $data:=[ { "v": 1 } ]; $data.{"v":$[].v} )
result should be:
{ "v": [ 1 ] }
but it is (version 1.8.6 of JSONata4Java):
{ "v": 1 }