I haven't done it with Firepower running ASA but I was able to follow a Thwack thread to get Kiwi CatTools' "big brother" product Solarwinds NCM to work with ASA running FTD. Basically I had to modify the device template following this guide:
https://thwack.solarwinds.com/thread/111738
I suspect a similar issue may be giving your Cattools issues.
In the past when I had problems with managing an ASA, I troubleshot it by temporarily allowing the management server to use telnet. Then I did a Wireshark capture on the management server filtered on the ASA address. Since telnet is plan text I was able to see the commands sent and responses received and modify the template accordingly.