Japanese input not working

[bahrta sai]

When I switch to the Japanese input no keyboard keys respond, including the Ctrl+Space key combination to switch between keyboards. I have to open the input methods menu on the taskbar to switch to another keyboard. Other keyboards work fine. I have a Russian keyboard & a Composekey keyboard which both work fine. It's only the Japanese IME that does this, & only occasionally at random. The others are fine. The Japanese ime allows you to create a custom dictionary which I do have, but it works most of the time without any problem.

[bahrta sai]

Using up-to-date HP Chromebook x360