Strange as they still supported drivers for older interfaces for catalina... Anyway i don't like the mic pre-amps on focusrite, too much coloured, but it's just a matter of taste.
OK. I'm not saying it's not supported (it very well might be, I just had a lot of issues with the driver on my old Mac and upgraded to the Focusrite Scarlett 3rd gen). Again, I don't know what to tell you - I think the pres sound better (unless I engage the AIR stuff, they aren't adding any color I can tell), the latency is much better, the Focusrite Control software gives me more control, and it doesn't give me the problems the Duo Capture EX does. If you want one I'll sell you mine cheap. I've mostly kept it around as a portable audio interface to run on battery power with an iPad.
EDIT: I just checked, Roland clearly lists the Roland Duo Capture EX as not compatible with Catalina. So yeah, it's no good to me either way - https://www.roland.com/global/support/support_news/19091015r/