[Tx Builder] Transaction cannot be built with an error "Invalid JSON RPC" on Polygon and Binance

[Jingranpm]

Describe the bug In Tx Builder step, when user tries to make a transfer on Polygon blockchain and Binance smart chain, after entering valid account addresses and amount, an error message pops up, preventing the transaction from being built.

To Reproduce Steps to reproduce the behavior:

1. Go to D4ft Wallet
2. Select Polygon blockchain
3. Enter valid addresses on Polygon Mumbai Testnet and a transfer amount (test addresses provided in Additional info below if needed)
4. See error

Expected behavior The transaction should be successfully built if all required information is provided correctly.

Screenshots Polygon Testnet

BSC Testnet

Additional context

• macOS Big Sur Version [11.2.3]

Additional info

• Polygon node config in D4ft

  

• Polygon Testnet setup on Metamask Wallet

• Addresses used on Polygon Testnet -- Sender public address (1 MATIC in account balance): 0xD897f0f0126a2a69153c461ECA5fE168E1bB52AB -- Receiver public address: 0xC0bDB46c8A508DfC7F88e657Eb72290257ac0441

• BSC node config in D4ft

  

• BSC Testnet account on Math Wallet

• Addresses used on BSC Testnet (from Math Wallet) -- Sender public address (0.2tBNB in account balance): 0x0ce41732d3a07db6dfce6ba493764088535763c1 -- Receiver public address: 0x02d778b1f7045d4e41f10932bdb805879b0c9ef8

[Jingranpm]

To confirm with dev: I am not sure if this error is produced due to different Chain ID configuration in Metamask Wallet (chain id: 80001) and D4ft Config (chain id: 1337). See details in screenshots above.