Hey there and welcome to the community:)
in version 5 of Blokada you can select to allow ipv6 as well. And you can use DoH servers in v5. Maybe this will fix your problem?
But before upgrading, please check the Blokada: Changelog whether all features you are currently using are already ported to v5. If you set manually blocked / allowed hosts my advice is to screenshot them, currently they are not being restored after the update to v5.