[Q&A] switchChainAsync() fails on WalletConnect + MetaMask mobile (Invalid chainId) before user accepts

[Jenny1610]

🧩 Context
I'm building a deposit flow using:

[email protected]
[email protected]
@web3modal/[email protected]

My users can switch between chains (e.g., BSC → Polygon) via a dropdown before deposit.
I use switchChainAsync({ chainId }) in the onSubmit of a form.

📱 Issue on MetaMask Mobile (via WalletConnect)
When calling switchChainAsync({ chainId }) on mobile with WalletConnect + MetaMask, I get an error:

This happens before the user even taps “Open MetaMask” in the WalletConnect modal (i.e., before the DApp has control again).
This behavior does not happen on desktop browsers.
And i saw the same issue on #4600 but it's closed with no solution.

✅ What I tried
Verified chain ID is valid and matches the dropdown selection.
Checked getAccount(wagmiConfig).connector.id === 'walletConnect'
Waited for getWalletClient() before calling switchChainAsync (no effect).
Tried delay/wait but issue persists.
Confirmed that MetaMask is already unlocked and on BSC.

🧠 Expected
I expect switchChainAsync to trigger the WalletConnect request → then user switches network in MetaMask → then returns control.
Currently, it fails before that can happen.

ℹ️ Questions

1. Is this a known limitation on WalletConnect + mobile?
2. Is there a workaround or correct way to wait for walletClient readiness before calling switchChainAsync()?
3. Do I need to defer the switch until user re-opens the dApp from MetaMask?