Version 2.0.4 of Zcashd includes a fix for the bug described here (https://z.cash/support/security/announcements/security-announcement-2019-03-19/).
Users should install this update and then rescan the blockchain by invoking zcashd -rescan. Sprout address balances shown by the zcashd wallet should then be correct.
Thank you to Alexis Enston for bringing this to our attention.