SaaS VSA unable to authenticate using API credentials, just says they are wrong

We had issues with the 1.4.x plugin, upgraded to the supposedly 2.0.2 but everything shows as 2.0.1 (I believe others have had this issue). But now since upgrading the plugin is completely broken, so now means it's not working/deploying at all. And it refuses to accept new API credentials. Have created new ones that are directly copy/pasted across from the Sophos portal, same role as the last ones and no joy. Also doesn't appear to be anywhere that logs what the actual error was or a way to see if anything else is going on.

Have opened a Partner case ID 05243641 but if we could get some action on this, given it may now mean that deployment of agents is not working.