Error when parsing redis aggregation reply. redigo: unexpected element type for Strings, got type []interface {} on reply position 4

I use redigo to use redis in golang

I have tried to use group with reducerTOLIST but I got the following error: Error parsing Aggregate Reply: redigo: unexpected element type for Strings, got type []interface {} on reply position 4

My request: FT.AGGREGATE user "toto" limit 0 1000 GROUPBY 1 @u_name reduce TOLIST 1 @_id AS u_id

Do you know if there is another way to do this request please ?

Thank!