Recently, some of the users claimed that ZEC withdrawal service is very slow, the clarification of this issue can be explained below.
Zcash wallet is the fork from Bitcoin Core 0.11.2, which means it has quadratic hashing issue inherited from Bitcoin. As a result of this, the collection of input transactions is very time consuming. It takes every 10 minutes for YUNBI to handle one ZEC withdrawal request.
Based on the issue above, YUNBI is working with Zcash developers to figure out the problem.
Please wait patiently if you have ZEC withdrawal issue.