Why do you not contact IDM support by email and ask IDM as recommended at top of every forum page?
I know only little about VT100 terminal emulation and so I read
Wikipedia - VT100. VT100 terminal emulation is from the Stone Age of computer age where surely nobody has thought about Chinese Unicode characters. I'm quite sure that with VT100 you get only ASCII characters and maybe also the ANSI characters to work.
Try the other
Terminal Emulation options. Try also the
ANSI Support options - see UltraEdit help page
SSH/Telnet Account Manager. But don't wonder if nothing helps.
One moment: Here is an FAQ
The Unicode HOWTO with an interesting point
4.2 Networking. Maybe using the Linux terminal emulation works.
Because the telnet client of UltraEdit is from
WEONLYDO Software I searched in their forums and found only this topic
UNICODE SUPPORT ???I think the UltraEdit users which use the Telnet console are only a small percentage. The number of users which use Telnet and are additionally reading regularly in the forum is even much more smaller. And the number of forum members which use telnet and additionally try it with Unicode is probably 1 (only you). Would be interesting for me if I'm right with that assumption.