Value expression strings on relational table update

[Lianto Lim]

I read in the documentation that "Value expression strings are used to compute a value which can then be assigned to a given field or column", but I can't get it working with relational table update function using nodejs @mysql/xdevapi@8.0.23.

Portion of code in node.js:
---
return customerTable.update()
.set("age", mysqlx.expr("age+1"))
.where("name = :name")
.bind('name', 'Andy')
.execute()
---
return an error: Unknown column 'doc' in 'field list'
and the log file shows the following query:
UPDATE `customers` SET `age`=(JSON_EXTRACT(doc,'$.age') + 1) WHERE (`name` = 'Andy')


Meanwhile, I test it on MySQL Shell 8.0, with the following portion of code:
---
customerTable.update().
set("age", mysqlx.expr("age + 1")).
where('name = :name').
bind('name', 'Andy').
execute();
---
it runs fine and show the following in the log file:
UPDATE `test`.`customers` SET `age`=(`age` + 1) WHERE (`name` = 'Andy')


Can someone help to point out the mistake?
Thanks