https://github.com/bitcoin/bitcoin/blob/d72758c3f6c34cd835f5de3efc230964f3b1ea56/src/torcontrol.cpp#L539

If a user is running Tor proxy outside localhost (perhaps on other host inside LAN or in containerised environment) , the automatic creation of onion services ends up creating an onion service listening to hardcored 127.0.0.1 address on the Tor proxy's host instead of the private address of the bitcoind – effectively running an empty onion service listening the Tor proxy's localhost.
{
    size_t vNodesSize;
    {
        LOCK(cs_vNodes);
        vNodesSize = vNodes.size();
    }
    if(vNodesSize != nPrevNodeCount) {
        nPrevNodeCount = vNodesSize;
        if(clientInterface)
            clientInterface->NotifyNumConnectionsChanged(vNodesSize);
    }
}
void CConnman::InactivityCheck(CNode *pnode)