Attachments containing Japanese names replace filenames with random numbers

Attached files containing Japanese text such as "日本語.png" ("Japanese.png") and "寿司の歴史.pdf"("History of Sushi.pdf") have their file names changed on their own.
It can look like a spam post. Also, since we don't know what the file is, there are accessibility issues.

If I change the name to English or Roman letters, the name change will not occur, but in addition to being troublesome, there is a problem because it is not only for people who understand English.