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.

{
    switch (m_net) {
    case NET_IPV4:
        return BIP155Network::IPV4;
    case NET_IPV6:
        return BIP155Network::IPV6;
    case NET_ONION:
        switch (m_addr.size()) {
        case ADDR_TORV2_SIZE:
            return BIP155Network::TORV2;
        case ADDR_TORV3_SIZE:
            return BIP155Network::TORV3;
        default:
            assert(false);
        }
    case NET_I2P:
        return BIP155Network::I2P;
    case NET_CJDNS:
        return BIP155Network::CJDNS;
    case NET_INTERNAL:   
    case NET_UNROUTABLE: 
    case NET_MAX:        
        assert(false);
    } 
    assert(false);
}
bool CNetAddr::SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size)
{
    switch (possible_bip155_net) {