Diskover - External ElasticSearch container

I am trying to setup Diskover, I already have an ElasticSearch container set up that I use for logs and a PDM server, lodestone.

I want to reuse that vs running two of them, especially because they are RAM hungry. When I point the LSIO diskover container at my ES container it seems to work, no errors in the log. However when I try and visit the Diskover page it won’t load anything. I saw a comment in a tutorial that the LSIO diskover container requires ES 5.XX. Is this still true? All the popular ELK stack images are using 7.xx