Hi Nick,
As you’ve probably noticed, Atik have removed the MaxIM drivers from their installer and recommend using an ASCOM driver instead.
However, you might try to get the Titan working using the original MaxIM plugin (https://www.atik-cameras.com/downloads/). You need to manually download the files and copy them into the MaxIM folder as documented.
Try setting it up as camera 1 (ie, pretend you only have one camera – the Atik Titan). If that works, then it should also connect as camera 2 (the guide camera in MaxIM).
Paul