Zoho Show Does Not Allow Text Input Using IMEs on Windows

I am trying to create a set of slides for presentation on Zoho Show on my Windows 10 PC. Since most of the text in it is going to be Japanese, I am using Japanese IMEs (one by Google and one by Microsoft). Either way, I cannot input Japanese text.

I've tried multiple browsers, but I get the same issue on Google Chrome, Firefox, and Microsoft Edge.

I've used Zoho Show for many years, and I think this is my first time to see an issue like this. There's no such problem with Zoho Writer, by the way.

Your prompt attention will be highly appreciated.

Thanks!

Yasuro