I use a Mac (Kstars 3.5.4). But also tried direct connection to a RPi3 running Stellarmate OS (1.5.1 and Kstars 3.4.1). No joy with any of those. The Dashboard shows the Atik USB hardware being there (ie the USB cables are working - tried 3 & all good). But when connecting w EKOS, that tab in the INDI drivers homepage doesn't even show.
I've conceded defeat I'm afraid - a FW shouldn't be this difficult to get to work (& it looks like lots of folks in other platforms have had problems w it on continued google searches) - will probably switch to a SX FW instead.