Unfortunately, it does sound like A2 support is giving you the runaround. Imunify360 is a security suite we have noticed more hosts putting on their sites. and blocking requests, so we added the extra message. You can generally tell by the “wsidchk” text in your response.
They should be able to white-list your Dashboards IP to pass through Imunify360, but that is really on their side and not much we can do from this end.
Another option will be if you are using Cloudflare to try to change the settings as listed in the
Imunify360 blog: Using Cloudflare “Cache Everything” with Imunify360
I apologize I don’t have a better response for you on that.
edit: A Cloudflare link mentioning A2 is using Imunify360
Super side note: I was looking into going to Recurring Revenue Retreat this year and enjoyed your blog post on it. 