MH> That being the case it sounds like when nested telnet sessions go to
 MH> non-Mystic systems, something isn't getting passed to the client for
 MH> negotiation.  Or maybe it is trying to negotiate with the original
 MH> (non-nested) telnet and not the client.  

If I had to guess whatever layer is being used (SIO, etc) doesn't do telnet
negotations at all or doesn't know when to request binary.

I need to set up a test with other systems so I can see if sending some telnet
commands as a client can resolve it.  I can't remember when the last time was
that I tried to test anything like this with a non-Mystic system (out of my
own "laziness" of not setting up another BBS software to test with) so I need
to do that to see what I can figure out.

--- Mystic BBS v1.12 A46 2020/06/11 (Windows/64)