[N1QL][ADVISE][RQG] advise returns an empty index recommendation

I have these buckets in the system:

multiple_table_db_79919484_simple_table_1
multiple_table_db_79919484_simple_table_10
multiple_table_db_79919484_simple_table_2
multiple_table_db_79919484_simple_table_3
multiple_table_db_79919484_simple_table_4

Running advise on this query
ADVISE SELECT t_1.int_field1 , t_1.decimal_field1 , t_1.primary_key_id , t_1.bool_field1 FROM bucket_01 t_1 LEFT JOIN bucket_05 t_1SiRAdlidCB ON ( t_1.primary_key_id = t_1SiRAdlidCB.primary_key_id ) LEFT JOIN bucket_010 t_1fLjtGGSnKf ON ( t_1.primary_key_id = t_1fLjtGGSnKf.primary_key_id ) INNER JOIN bucket_04 t_1GHMwUzdukS ON ( t_1.primary_key_id = t_1GHMwUzdukS.primary_key_id ) INNER JOIN bucket_04 t_1LjVrlSNfDc ON ( t_1.primary_key_id = t_1LjVrlSNfDc.primary_key_id ) WHERE ((t_1.primary_key_id IS NOT NULL AND t_1.int_field1 IS NULL)) OR ((t_1.int_field1 >= 47635891 OR t_1.varchar_field1 IS NOT NULL));

Gets this recommendation

Covered Index Recommendations
CREATE INDEX adv_primary_key_id ON `bucket_05`(`primary_key_id`)

CREATE INDEX adv_primary_key_id ON `bucket_010`(`primary_key_id`)

CREATE INDEX adv_primary_key_id ON `bucket_04`(`primary_key_id`)

CREATE INDEX adv_primary_key_id ON `bucket_04`()

Index Recommendations
CREATE INDEX adv_int_field1_primary_key_id ON `bucket_01`(`int_field1`,`primary_key_id`)
CREATE INDEX adv_varchar_field1 ON `bucket_01`(`varchar_field1`)

There is one blank index being recommended, plus it says those indexes are covering but they do not include fields from the predicate?