Logstash failing to index field

I noticed a large amount of failures from Logstash failing to index the tls.server.ja3s field. I am running Rock 2.5 and I made sure to pull down the latest index patterns and mapping.

[2020-05-22T13:50:26,499][WARN ][logstash.outputs.elasticsearch][main] Could not index event to Elasticsearch. {:status=>400, :action=>["index", {:_id=>nil, :_index=>"ecs-suricata-network-2020.05.22", :routing=>nil, :_type=>"_doc"}, #<LogStash::Event:0x5f1adf97>], :response=>{"index"=>{"_index"=>"ecs-suricata-network-2020.05.22", "_type"=>"_doc", "_id"=>"ZkqmPHIBEgV_tpUwOhKf", "status"=>400, "error"=>{"type"=>"mapper_parsing_exception", "reason"=>"failed to parse field [tls.server.ja3s] of type [keyword] in document with id 'ZkqmPHIBEgV_tpUwOhKf'. Preview of field's value: '{string=771,49199,65281-11-35, hash=ccc514751b175866924439bdbb5bba34}'", "caused_by"=>{"type"=>"illegal_state_exception", "reason"=>"Can't get text on a START_OBJECT at 1:1208"}}}}}

This error appears to be stopping Logstash after some time. Anyone else seeing this in their logs?