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.
int RPCPort() const { return nRPCPort; }
    CBaseChainParams() = delete;
    CBaseChainParams(const std::string& data_dir, int rpc_port) : nRPCPort(rpc_port), strDataDir(data_dir) {}
private:
    int nRPCPort;
    std::string strDataDir;
};
/**
 * Creates and returns a std::unique_ptr<CBaseChainParams> of the chosen chain.
 * @returns a CBaseChainParams* of the chosen chain.
 * @throws a std::runtime_error if the chain is not supported.
 */
std::unique_ptr<CBaseChainParams> CreateBaseChainParams(const std::string& chain);
/**
 *Set the arguments for chainparams
 */
void SetupChainParamsBaseOptions(ArgsManager& argsman);
/**
 * Return the currently selected parameters. This won't change after app
 * startup, except for unit tests.
 */
const CBaseChainParams& BaseParams();
void SelectBaseParams(const std::string& chain);
#endif