Ok, I think I've found a solution to this. For anyone interested, I found this topic which is almost identical to my question: https://forum.mikrotik.com/viewtopic.php?p=1073976#p1073976 I followed @CGGXANNX suggestion regarding the ULA, and now it is working. I get replies from pihole answering to ...

Hello to everyone, I have a configuration issue, involving pihole running and ipv6. I have installed a container, pihole, which is running without issues. I am using dual stack ip and ipv6, and the configuration for ipv4 through the dhcp server of mikrotik is working like expected. The clients are g...