Keyboard shortcut lookup fails when keyboard layout is not US

When pasting using Ctrl-Shift-V a ^V is inserted before the text. This only happens when my keyboard layout is set to Bulgarian Phonetic. I'm using Cinnamon DE.

In the screenshot below, the first paste is when I hit Ctrl-Shift-V in US keyboard layout, the second one is in Bulgarian.

I tried narrowing the cause down but eventually got to the invocation of vte_terminal_paste_clipboard. Now I'm not sure if it's VTE or XFCE Terminal, just that the problem is not present in 0.8.x series.