Solidity Polygon: Accessing ETH Mainnet Data via Polygon Contract

The issue is that your contract is not deployed on Mainnet.

It is deployed on Testnet, but on Mainnet there is no contract code associated with the address.

You should try to deploy it again on Mainnet. As you know, if you use the same address and same nonce as on testnet, you should have the same address for your Mainnet contract.

If you want to receive the MATIC that you sent to the address back, you should add a withdraw function to your contract that transfers all the contract balance to msg.sender. Otherwise, this MATIC will be lost forever.

EDIT: I think that this is your contract on Mainnet. The address is not the same as on Testnet, althought they both start by 0x39! You called the wrong address on Mainnet.

Difference between ETH and Polygon smart contracts

There is none. Polygon runs barely modified GoEthereum, same as Ethereum mainnet, which runs EVM virtual machine.

Your smart contracts are deployable across all EVM compatible chains, like Polygon, Avalanche, Binance Smart Chain, Fanton, Telos EVM and couple of other chains.