Can upgradeProxy on polygon mumbai testnet

Hello,

I'm currently facing issue while using upgradeProxy function in "@openzeppelin/truffle-upgrades".

I use command 'truffle compile --all && truffle migrate --network mumbai'

When 3_deploy_upgrade.js executed, I think upgradeProxy function is not excuted. Just [object Object] is printed in console and not deploy upgradeMyToken contract. But in rinkeby network, it works fine. I'm not sure why I can't upgrade contract on mumbai.

Any clue?

Thanks.

:1234: Code to reproduce

MyToken.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;

import "@openzeppelin/contracts-upgradeable/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/ERC721URIStorageUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

contract MyToken is Initializable, ERC721Upgradeable, ERC721URIStorageUpgradeable, OwnableUpgradeable, UUPSUpgradeable {
    function initialize() initializer public {
        __ERC721_init("MyToken", "MTK");
        __ERC721URIStorage_init();
        __Ownable_init();
        __UUPSUpgradeable_init();
    }

    function safeMint(address to, uint256 tokenId) public onlyOwner {
        _safeMint(to, tokenId);
    }

    function _authorizeUpgrade(address newImplementation)
        internal
        onlyOwner
        override
    {}

    function _burn(uint256 tokenId)
        internal
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
    {
        super._burn(tokenId);
    }

    function tokenURI(uint256 tokenId)
        public
        view
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
        returns (string memory)
    {
        return super.tokenURI(tokenId);
    }
}

UpgradeMyToken.sol

// UpgradeMyToken.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;

import "@openzeppelin/contracts-upgradeable/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/ERC721URIStorageUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

contract UpgradeMyToken is Initializable, ERC721Upgradeable, ERC721URIStorageUpgradeable, OwnableUpgradeable, UUPSUpgradeable {
    string private aa;

    function initialize() initializer public {
        __ERC721_init("MyToken", "MTK");
        __ERC721URIStorage_init();
        __Ownable_init();
        __UUPSUpgradeable_init();
    }

    function getAA() external view onlyOwner() returns (string memory) {
        return _aa;
    }

    function safeMint(address to, uint256 tokenId) public onlyOwner {
        _safeMint(to, tokenId);
    }

    function _authorizeUpgrade(address newImplementation)
        internal
        onlyOwner
        override
    {}

    function _burn(uint256 tokenId)
        internal
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
    {
        super._burn(tokenId);
    }

    function tokenURI(uint256 tokenId)
        public
        view
        override(ERC721Upgradeable, ERC721URIStorageUpgradeable)
        returns (string memory)
    {
        return super.tokenURI(tokenId);
    }
}

2_deploy.js

const { deployProxy } = require('@openzeppelin/truffle-upgrades');

const MyToken = artifacts.require("MyToken");

module.exports = async function (deployer, network) {
  const instance = await deployProxy(MyToken, [], { deployer });
};

3_deploy_upgrade.js

const { upgradeProxy } = require('@openzeppelin/truffle-upgrades');

const MyToken = artifacts.require("MyToken");
const UpgradeMyToken = artifacts.require("UpgradeMyToken");

module.exports = async function (deployer, network) {
  const existing = await MyToken.deployed();
  const instance = await upgradeProxy(existing.address, UpgradeMyToken, { deployer });
};

truffle-config.js

mumbai: {
      provider: () => new HDWalletProvider(common.PRIVATE_KEY_DEV, common.RPC.mumbai),
      network_id: 80001,
      from: common.ADDRESS_DEV,
      confirmations: 2,
      timeoutBlocks: 200,
      skipDryRun: true,
    },
rinkeby: {
      provider: () => new HDWalletProvider(common.PRIVATE_KEY_DEV, common.RPC.rinkeby),
      network_id: 4,
      from: common.ADDRESS_DEV,
      confirmations: 2,
      timeoutBlocks: 200,
      skipDryRun: true,
    },

:computer: Environment

"@openzeppelin/contracts-upgradeable": "^4.2.0",
"@openzeppelin/truffle-upgrades": "^1.8.0",
"@truffle/hdwallet-provider": "^1.4.2",
"truffle": "^5.4.2"

Is there any information on the console other than "[object Object]"? I'm not a mumbai user myself so it's not simple for me to test this.