KnowBe4 PAB no headers found error

We have had this issue wince April, but when on-premise users click the PAB they get the "No headers found error."

* Important information: * We are a Hybrid org * We are also GCC * The extension is deployed via manifest file in both 365 and EXCH 2019 * the damn thing used to work fine

Have been deep diving this with their support and they indicate that the REST API is in preview mode.

Researching the error I found the following stating that the REST API should not be used: [https://techcommunity.microsoft.com/t5/exchange-team-blog/the-end-of-the-rest-api-for-on-premises-mailboxes-preview/ba-p/3221219](https://techcommunity.microsoft.com/t5/exchange-team-blog/the-end-of-the-rest-api-for-on-premises-mailboxes-preview/ba-p/3221219) [https://techcommunity.microsoft.com/t5/exchange-team-blog/reminder-end-of-rest-api-for-on-premises-mailboxes-preview/ba-p/3828889](https://techcommunity.microsoft.com/t5/exchange-team-blog/reminder-end-of-rest-api-for-on-premises-mailboxes-preview/ba-p/3828889)

Now they are essentially telling us to take it up with Microsoft, when I explain that MS says to not use REST for on-prem, they repeat telling us to take it up with MS.

Am I missing something? Is there some setting that I need to set in our tenant that I just cannot find?

Is anyone else having this issue with the KnowBe4 PAB?

UPDATE: KB4 Finally caved once it started to make a bunch of noise on their support forms and created a version that does not use REST. this one seems to have no issues at the moment. If you are haivng the issue still, contact support.