I have the same issue with German and Finnish keyboard layouts via ibus (umlauts and other non-ASCII characters don't work) and ibus-anthy after the update from 2.80.0-9 to 2.80.0-10, downgrading fixes it. So it looks like that security fix breaks ibus with GTK applications in general. :-(
Stopping ibus makes the system keyboard layout (German in my case) work.
