When spawning a vault from a multisig vesting account, the wallet thinks it's a single sig

[noamnelke]

Steps to reproduce

1. Create multisig vesting account (with more than one signature required).
2. Create matching vault.
3. Spawn the vesting account.
4. Create a spawn transaction from the vesting account for the vault. Continue to the signing screen.

What's expected? The wallet should display a "Sign & Export" button, since a single signature is not enough. After signing, exporting and importing into a wallet with other keys, the wallet should show the "Sign & Publish" option, once enough signatures are ready.

What happens? The wallet shows a "Sign & Publish" button. Clicking it results in a transaction validation error (since more signatures are required). If manually trying to export the signed transaction instead of publishing, the wallet fails to import the transaction with an error message.

Screengrabs "Sign & Publish" button displayed, even though it's a 2-of-3 multisig vesting account

"Failed to verify transaction" error displayed after clicking the "Sign & Publish" button (the other error is because I earlier tried to import a transaction exported manually)

Error message when trying to import a transaction exported manually (by opening the drop-down and selecting "Sign & Export")