I have the same problem on ubuntu 18.10 on gnome terminal (the problem appeared after upgrading from an 17.04ubuntu).
*xev gnome terminal output (in gnome terminal ^ doesn't work)*
KeyPress event, serial 37, synthetic NO, window 0x2c00001, root 0x2ac, subw 0x0, time 12476575, (1386,-67), root:(1426,349), state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES, XLookupString gives 1 bytes: (5e) "^" XmbLookupString gives 1 bytes: (5e) "^" XFilterEvent returns: False
KeyRelease event, serial 37, synthetic NO, window 0x2c00001, root 0x2ac, subw 0x0, time 12476723, (1386,-67), root:(1426,349), state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES, XLookupString gives 1 bytes: (5e) "^" XFilterEvent returns: False
*xev terminator output (in terminator ^ works perfectly)*
KeyPress event, serial 37, synthetic NO, window 0x2a00001, root 0x2ac, subw 0x0, time 12700278, (680,1395), root:(756,1613), state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES, XLookupString gives 1 bytes: (5e) "^" XmbLookupString gives 1 bytes: (5e) "^" XFilterEvent returns: False
KeyRelease event, serial 37, synthetic NO, window 0x2a00001, root 0x2ac, subw 0x0, time 12700465, (680,1395), root:(756,1613), state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES, XLookupString gives 1 bytes: (5e) "^" XFilterEvent returns: False
I have the same problem on ubuntu 18.10 on gnome terminal (the problem appeared after upgrading from an 17.04ubuntu).
*xev gnome terminal output (in gnome terminal ^ doesn't work)*
KeyPress event, serial 37, synthetic NO, window 0x2c00001,
root 0x2ac, subw 0x0, time 12476575, (1386,-67), root:(1426,349),
state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES,
XLookupString gives 1 bytes: (5e) "^"
XmbLookupString gives 1 bytes: (5e) "^"
XFilterEvent returns: False
KeyRelease event, serial 37, synthetic NO, window 0x2c00001,
root 0x2ac, subw 0x0, time 12476723, (1386,-67), root:(1426,349),
state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES,
XLookupString gives 1 bytes: (5e) "^"
XFilterEvent returns: False
*xev terminator output (in terminator ^ works perfectly)*
KeyPress event, serial 37, synthetic NO, window 0x2a00001,
root 0x2ac, subw 0x0, time 12700278, (680,1395), root:(756,1613),
state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES,
XLookupString gives 1 bytes: (5e) "^"
XmbLookupString gives 1 bytes: (5e) "^"
XFilterEvent returns: False
KeyRelease event, serial 37, synthetic NO, window 0x2a00001,
root 0x2ac, subw 0x0, time 12700465, (680,1395), root:(756,1613),
state 0x11, keycode 21 (keysym 0x5e, asciicircum), same_screen YES,
XLookupString gives 1 bytes: (5e) "^"
XFilterEvent returns: False