Non-English text disappears in email sent via our website

We are unable to send Japanese text in our emails sent via the FTH-hosted Toastmaster website. We can enter it into the body of the email draft, however after we send it, the actual email sent out will have all Japanese text omitted. Actually, the Japanese text in the agenda (such as role titles and descriptions) will also be omitted. Since we are a bilingual club, this is very important to us. As a workaround, we have been pasting screenshots of our Japanese text as image files into the email instead. However, this is not ideal since it’s unintuitive for some people, and we cannot copy/paste off of an image file into a translator in case anyone wanted to do that. Is there a solution to this?

This seems like a common issue, but I could not find a resolution. Please let me know whether or not this can be addressed. Thank you in advance for any help you can provide.

For the below information that was requested…
When did your issue 1st occur?   What operating system, browser, & browser version are you using?  Did you refresh your browser cache? Are your cookies enabled? Lastly, a  screen shot  is often helpful.
This issue has occurred since 10/31/19 as the first instance of it happening that I could find. This occurs on any system, browser, or browser version. I have included screenshots.

FTH only supports the UTF-8 character set. We do not support double byte characters such as used in many Non-romanic languages.