OpsGenie not acking through to LogicMonitor, when LM is using SSO

Hello,

I have an LM installation with an OpsGenie integration. This uses an API to go to OG, which works fine, but the back-channel acking from OpsGenie to LogicMonitor doesn't work, either by the stated UserID and Password, as per the documentation, or via API tokens. The username and password credential works fine when logging into LogicMonitor, and the token method works via a Python script test, but the OpsGenie debug says "authentication failed"

It looks like the OpsGenie documentation fails after LM turns on SSO. This has to be a common implementation... Has anyone found out how to make this work? Any tips?