ZCash withdrawal issue

[rob1997]

What

There have been 2 zcash users who are experiencing issues with their funds getting stuck on the snap. Investigate, Verify then fix.

How to Reproduce

• @sqhell please fill this in I don't have enough context

Expectation

Successful funds withdrawal

Additional Context (optional)

• Slack Thread
  @sqhell if you've screenshots/emails you would like to reference here please add them

Estimation

@sqhell feel free to put in your own estimations

Dependencies

[sqhell]

This was simply caused by the sync not looking far back enough when an existing wallet is added to the snap. I have added logic to do this, and allow user to enter a birthday block height if they wish to trigger a sync. This can take ~40 minutes with older wallets and will be working with the NU6.1 PR which I should have done early next week