Could try ad below directive in seperate new config file /etc/dnsmasq.d/99-my-settings.conf:
bind-interfaces
pihole-FTL might skip trying to bind to that 127.0.0.2 ip and hopefully start.
Or else you need to configure pihole-FTL to only listen on particular IP's.
And same with stubby ... need to tell it to only listen on 127.0.0.2.