My instance is going through the same problem. We require a solution

We can not put this into Production without Non-logged users being able to access the Virtual Agent our Product Leadership has decided.  Can not Urge enough that Atlassian enable the Virtual Agent to all portal users ASAP. 

The published documentation on the site regarding use of VA does NOT mention the qualification that it is only available for users signed-in. Therefore, the VA availability to users should be, needs to be, based upon project portal settings. In our case, available for all users.

The Virtual Agent needs to support all those access the portal. They should not have to have a customer account created and signed into it as a minimum. As the portal can be set to allow non-signed users, the Virtual Agent, that runs underneath the those settings, must adhere to those settings, not have independent settings that override established settings that we control.

This Virtual Agent is in Beta, and therefore should not require a (useless IMO) feature request that sits for years. We request this open user be enabled in Beta now for all users - such as the configuration allows for such users to use the portal in a productive manner.