I am using Java Swing GUI wallet 0.68 (beta) version
I think its the wallet. But it is very weird that it does not do it with all the t-addresses
Let me try to ping the Wallet dev.
This "wallet" is really just a UI for a subset of the RPC interface related to addresses and transactions. It holds no keys, knows not whether it's Zero or Zclassic or whatever. Only the port it connects to and the labels it prints next to the amounts change.
So, if there is an issue with Z addresses, it should be showing up in other coins as well.
Tearo