Filebeat service doesn't send log

It is a file in which XML lines are continuously written. When the service starts it reads the data and sends it to logstash and elasticsearch indexes it without any problem. I see them in Kibana.
But then the file is indicated as if there is no modification while it is continuously fed since every action is transcribed in the file.

That's where I'm lost, how can I get Filebeat to detect the new lines? Do I have to implement some kind of tag on the last line he read? Do I need to change the Filebeat configuration? Do I have to use another product than Filebeat?

Thank you for the support.