Question on Date Processor

I have a field that is currently set as 'keyword' and I want to convert it to be 'date'.

I have added the Date processor in my ingest pipeline. I have set the formats to be "YYYY-MM-dd HH:mm:ss,SSS"

I have the target field to be same as the field value.

When I do a test with a document the input of "2024-12-03 19:13:28,143" is converted to "2024-01-01T19:13:28.143Z"

It appears that it is not liking the date? The time is the same but the date portion of it is converted from 2024-12-03 to 2024-01-01 for some reason.

What am I missing?