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.
#include <chainparamsbase.h>
#include <tinyformat.h>
#include <util/system.h>
#include <util/memory.h>
#include <assert.h>
const std::string CBaseChainParams::MAIN = "main";
const std::string CBaseChainParams::TESTNET = "test";
const std::string CBaseChainParams::SIGNET = "signet";
const std::string CBaseChainParams::REGTEST = "regtest";
void SetupChainParamsBaseOptions(ArgsManager& argsman)
{
    argsman.AddArg("-chain=<chain>", "Use the chain <chain> (default: main). Allowed values: main, test, signet, regtest", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-regtest", "Enter regression test mode, which uses a special chain in which blocks can be solved instantly. "
                 "This is intended for regression testing tools and app development. Equivalent to -chain=regtest.", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-segwitheight=<n>", "Set the activation height of segwit. -1 to disable. (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
    argsman.AddArg("-testnet", "Use the test chain. Equivalent to -chain=test.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-vbparams=deployment:start:end", "Use given start/end times for specified version bits deployment (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-signet", "Use the signet chain. Equivalent to -chain=signet. Note that the network is defined by the -signetchallenge parameter", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-signetchallenge", "Blocks must satisfy the given script to be considered valid (only for signet networks; defaults to the global default signet test network challenge)", ArgsManager::ALLOW_STRING, OptionsCategory::CHAINPARAMS);
    argsman.AddArg("-signetseednode", "Specify a seed node for the signet network, in the hostname[:port] format, e.g. sig.net:1234 (may be used multiple times to specify multiple seed nodes; defaults to the global default signet test network seed node(s))", ArgsManager::ALLOW_STRING, OptionsCategory::CHAINPARAMS);
}
static std::unique_ptr<CBaseChainParams> globalChainBaseParams;
const CBaseChainParams& BaseParams()