How to make the changes in filebeat effective

[warkolm (Mark Walkom)]

It makes sense, but please provide the information requested.
Specifically the entire document that was output, not just a section of it.

[aagarwal3]

logs of dec 16:

    @timestamp	Dec 16, 2020 @ 18:59:59.715
	_id	_KCkbnYBaWc7eVWEZIer
	_index	log-2020.12.17
	_score	 - 
	_type	_doc
	agent.ephemeral_id	59068176-f55f-437b-97b8-a0933dd9d968
	agent.id	c2863c1e-bc3d-4d18-8be4-d5db8b214edc
	agent.name	VM_0_16_centos
	agent.type	filebeat
	agent.version	7.10.0
	ecs.version	1.6.0
	input.type	log
	log.file.path	somefilepath
	log.offset	172,959,393
	message	[sometext1] [2020-11-30 02:10:17.736] [loglevel] [sometext2] msg

recent log

    @timestamp	Jan 5, 2021 @ 12:56:38.165
	_id	SUVW1HYBaWc7eVWEYHkl
	_index	log-node2-2021.01.06
	_score	 - 
	_type	_doc
	agent.ephemeral_id	ad80e8ba-bbac-4e2c-a33b-09135f3b6553
	agent.id	c2863c1e-bc3d-4d18-8be4-d5db8b214edc
	agent.name	VM_0_16_centos
	agent.type	filebeat
	agent.version	7.10.0
	dissect.start_time	2021-01-06 04:56:33.698
	ecs.version	1.6.0
	input.type	log
	log.file.path	somefilepath
	log.offset	169,458,666
	message	[sometext1] [2021-01-05 09:56:17.736] [loglevel] [sometext2] msg

dissect.start_time is working only on recent logs not on previous ones.I do not think that logs which are sent to ES can have the changes made in filebeat. I just simply added add_host_metadata: and they are not visible in Dec 16,2020 logs.