Display name field Title auto revert

We use sharepoint in Japanese language.
And in early 2023, we created a sharepoint list. In that list, we changed the display name of the field "Title" form "Title" to "件名".
By the end of 2023, we received a notification from the end-user that the display name of the "件名" field was incorrect.
When we checked, the Display name of the field "件名" had been changed back to "Title".
Please help me check the reason why.
Also, will this happen again in the future?