That's probably an issue with EletrumZCL's unique server.

I downloaded the wallet to try and most of the time it doesn't sync and the big circle at the bottom-right corner goes red. But after closing and opening the wallet a few times, the wallet starts to sync (stay green for a few seconds/minutes, goes red and sync again). Try to do that until you can spend your coins.

Maybe you should also create a new issue here: https://github.com/BTCP-community/electrum-zcl/issues