Not work hotkey Ctrl+Space

Matlab R2021b, I writed code Ctrl+Space worked, but now no. How that option in shortcut named?

[DGM]

I don't see any mention of such a shortcut in the defaults described by documentation or any of the versions I have. If it's something custom you set, you're the only one who would know. If it's some system-level shortcut or some default that I don't know about, then you'll have to describe what it did.