I have tried changing the config option to remove the <'s around the username. I have tried resetting the config and running through a yaml parser, essentials works, but I can never remove the brackets.

I have the same problem. I get this when loading it up:

20.11 01:09:04 [Server] INFO [01:09:04 INFO]: [EssentialsChat] Enabling EssentialsChat v2.0.1-b174

So the plugin is enabled
However, when I reload EssentialsChat with Plugman, the chat format kicks in (Of course without hooking on to anything else)
And Yes I do have Vault

Regular or X. I already have the EssentialsXChat plugin

Then the plugin didn't enable or something. Do you have vault?

Install EssentialsChat.

Yes, I have Vault