When using "Fill & Sign", I was able to input both Japanese and alphanumeric characters directly, but suddenly, only Japanese is reflected in the small IME window (aka "green arrow") that appears in the upper left corner of the screen, and it is not reflected in a given location in the PDF unless converted and entered.

I am using it on Windows 10, but it seems to be occurring on Windows 11 and other versions as well.

Please figure out the cause and fix the program.