Building geo_point object during migration from Mysql to Elastic using Logstash - mysql

Question

I'm struggling to be able to provide geo_point as an object in one of my indexes.
Migration works smoothly for other types: geohash, string etc. but developer requested specifically to have object there.
I'm using Logstash/Elastic 7.6 with mysql 8.0 JDBC driver on CentOS 7. Index has template with mapping as geo_point for this specific column.
Query in Mysql uses JSON_OBJECT to build it (but I tried different approaches with CONCAT() as well):
JSON_OBJECT('lat', latitude, 'lon', longitude) as geo_point
Data is there (no issue with nulls), but I receive error like this:
[2020-07-27T17:29:14,978][WARN ][logstash.outputs.elasticsearch] Could not index event to Elasticsearch. {:status=>400, :action=>["index", {:_id=>"264a4b7994a2867fe1bfba7a3fbaa0ba", :_index=>"elastic_index", :routing=>nil, :_type=>"_doc"}, #<LogStash::Event:0x22952f4a>], :response=>{"index"=>{"_index"=>"live_listings-pub_1_test_200725", "_type"=>"_doc", "_id"=>"264a4b7994a2867fe1bfba7a3fbaa0ba", "status"=>400, "error"=>{"type"=>"mapper_parsing_exception", "reason"=>"failed to parse field [geo_point] of type [geo_point]", "caused_by"=>{"type"=>"parse_exception", "reason"=>"latitude must be a number"}}}}}
Is there a way to do it in the mysql query or is there another way to do it maybe with filter functionality?
Would appreciate any help or point me in right direction.
Thanks.