Those seem to be debug messages, which you can toggle under the “Select properties” combo box in the top right. You can probably find a way to filter out logs from the unit “maliit-keyboard” too. It’s not really a bug.
Is there any working virtual keyboard under Wayland for Plasma 5.27 ? I need it on non touch screen and being able to type using mouse (for a family member with a disabled hand) like how Onboard works on X11.