EIP712: signer._signTypedData() not triggering metamask signature

[jmsofarelli]

I am using ethers v5.7.2 and I the following code:

const signature = await signer._signTypedData(data.domain, data.types, data.message);
console.log('signature', signature);

Nothing happens: no Metamask signature request, no errors, no log in console!

Everything else looks fine: data.domain, data.typesand data.message.

Also signer._signTypedData is present:

_signTypedData(domain, types, value) {
        return __awaiter(this, void 0, void 0, function* () {
            // Populate any ENS names (in-place)
            const populated = yield _ethersprojec…

When I use the following code, the signature request IS actually triggered in Metamask:

const [method, argData] = ['eth_signTypedData_v4', JSON.stringify(data)];
const signature = await signer.provider.send(method, [from, argData]); 
console.log('signature', signature);

Any idea about what is happening?