It's not clear to me if dropping support for this functionality was intentional.

Chain of events:

- #21689 removed test coverage due to a misunderstanding due, I believe, to this functionality being generally supported by all platforms except macOS which does not and returns a different format
- #21756 removed support and caused this regression
- #21690 restores the test coverage that would have caught this regression

Currently, neither the test coverage before #21689 nor the coverage restored by #21690 pass since the merge of #21756.

{
    return valid;
}
bool CSubNet::SanityCheck() const
{
    switch (network.m_net) {
    case NET_IPV4:
    case NET_IPV6:
        break;
    case NET_ONION:
    case NET_I2P:
    case NET_CJDNS:
        return true;
    case NET_INTERNAL:
    case NET_UNROUTABLE:
    case NET_MAX:
        return false;
    }
    for (size_t x = 0; x < network.m_addr.size(); ++x) {
        if (network.m_addr[x] & ~netmask[x]) return false;
    }
    return true;
}
bool operator==(const CSubNet& a, const CSubNet& b)