Grafana 6.3.5 error 502 connecting to Elasticsearch 7.3.0 datasource

I am running Grafana 6.3.5 and Elasticsearch 7.3.0 both in dock containers on Windows 10. I am getting an error 502 trying to connect to an Elasticsearch datasource. InfluxDB datasources are workiogn fine. I am able to get to Kabana and load its home page via http://localhost:5601. I can also get to Grafana at http://localhost:9200. Here is what it returns:

“name” : “elk”,
“cluster_name” : “elasticsearch”,
“cluster_uuid” : “Oh6gWd-8Sw2mD1xYSD0qDg”,
“version” : {
“number” : “7.3.0”,
“build_flavor” : “default”,
“build_type” : “tar”,
“build_hash” : “de777fa”,
“build_date” : “2019-07-24T18:30:11.767338Z”,
“build_snapshot” : false,
“lucene_version” : “8.1.0”,
“minimum_wire_compatibility_version” : “6.8.0”,
“minimum_index_compatibility_version” : “6.0.0-beta1”
“tagline” : “You Know, for Search”

ELK Logs (–taill 500)

Grafana Logs (–tail 500)

Not sure what to try next. This was working with older versions on my machine which died a few days ago. I was running ELK 6.7 at the time and the latest version of Grafana. I tried to revert back and it is not working either.