timestamps not working in a deep array of subdocument

Question

So, im using nestjs to create a rest api and here is my schema

user.schema

repository.schema

commit.schema

as you can see i also set timestamps: true in repository.schema it work but when i set it on commit.schema the timestamps not generating the createdAt and updatedAt field

here is the result that i get

post result

i already google this one but still can't find the solution!

thanks in advance