After pressing Ctrl-C, sqlcl is interrupted. If code page chcp 65001, cmd.exe becomes unusable. Commands are not fully entered and SQL and OS prompts are switched back and forth. Below example, after starting sqlcl, i press Ctrl-C, then Enter, then Enter:
D:\>chcp 65001
Active code page: 65001
D:\>sql /nolog
SQLcl: Release 23.3 Production on Tue Oct 17 11:47:09 2023
Copyright (c) 1982, 2023, Oracle. All rights reserved.
SQL>
SQL> ^C
D:\>
D:\>
SQL>
D:\>
SQL>