urxvt 14755, unicode character will not insert
 

Google has failed me. I am using urxvt, with 14755 support. I hold ctrl+shift, the box appears, I type a hex and see the symbol I want, all is good. Then I hit enter, space, or let go of ctrl+shift.... nothing happens, symbol is not inserted, not even a '?' mark.

doesn't work in bash, zsh, screen, vim, local host, ssh session, or any combination/isolation of them.

Env:
LANG=en_US.utf8
LC_ALL=en_US.utf8

I can copy and paste unicode characters using the mouse, though most appear as '?'.