Filebeat 'replace' processor cant be empty

Elastic Stack Beats
1

Hey, I just upgraded to filebeat 8.15.0 and now my filebeat config isn´t working anymore.

If the replacement is an empty string, filebeat wont start.

      - replace:
          fields:
            - field: "host.hostname"
              pattern: ".my.domain"
              replacement: ""

I get the following error:

{"log.level":"error","@timestamp":"2024-09-03T05:43:17.517Z","log.origin":{"function":"github.com/elastic/beats/v7/libbeat/cmd/instance.handleError","file.name":"instance/beat.go","file.line":1349},"message":"Exiting: error initializing processors: failed to unpack the replace configuration: string value is not set accessing 'processors.34.replace.fields.0.replacement' (source:'/etc/filebeat.yml')","service.name":"filebeat","ecs.version":"1.6.0"}

Is there another way I can replace/delete a part of a string in my host.hostname field? Or is this behaviour a bug?

Edit: I changed my replacement from an empty string to a space, but this is a bad workaround because in Kibana I need to add this space after my host.hostname otherwise my filter doesn´t work.

Edit 2: I use the "Script Processor" now, as long as I don´t know if this is a bug or not. Here is my code if anything is facing a similar issue:

      - script:
          lang: javascript
          source: >
            function process(event) {
              var hostname = event.Get("host.hostname");
              var domain = '.my.domain';
              var updatedHostname = hostname.slice(0, -domain.length);
              event.Put("host.hostname", updatedHostname);
              return event;
            }