Token import fails silently on custom networks when address matches a mainnet token

Feature Requests
1

Hi MetaMask team,

We ran into an issue when using MetaMask connected to a custom network (specifically a Tenderly VNet, which is a fork of Ethereum mainnet).

When trying to import an ERC-20 token by contract address on a custom network, MetaMask displays this warning:

“This address matches a known Ethereum Mainnet token address. Recheck the contract address and network for the token you are trying to add.”

Token details auto-fill correctly, but clicking Import tokens does nothing — no error, no confirmation, no token added. The warning is informational so the import should still go through.

Reproduced consistently on a mainnet fork. The same import worked with a different wallet.

Is this a known issue or a bug?

Thanks

2

The issue might be due to the way tokens are recognized on non-standard networks; MetaMask compares addresses with the mainnet database and does not recognize forks. You can also contact MetaMask support about this . they will probably be able to assist you better

3

You can also first add the network as a custom network, then switch to this network and try to add the token manually and as a custom token again