Column has [object Object] values instead of dates

[ksure]

Hello! I'm trying to convert a string column to a date. (We use Trino for querying the data in Looker)

The date column named "date_str" has dates like 

2024-04-24-233510.065730

Here's how I'm extracting the date, as a custom dimension, in the lkml file:

dimension: conv_date {
    type: time
    sql: parse_datetime(${TABLE}.date_str, 'yyyy-mm-dd-HHmmss.SSSSSS') ;;
}

However, in looker studio, the column is filled with values [object Object]

Any pointers would be helpful!