Upgrading from routeros v6.49.2 to v7.1.1 results in a not working configuration when using a configured network list (/routing bgp network) with IPv4 and IPv6 prefixes.
When upgrading the configuration migration will convert this list in two address lists called 'bgp-networks', one in /ip/firewall/address-list and one in /ipv6/firewall/address-list. The BGP peer configuration is updated with the setting output.network with the value 'bgp-networks'.
In this configuration, none of the networks in the address-lists are announced. The creation of IPv4 and IPv6 address lists with the same name seems to be causing the issue, when renaming one of the address-list names fixes the issue.
This raises another issue: it seems impossible to announce an address-list with IPv4 and IPv6 addresses to the same peer. This was possible in v6.