What's the stock text editor app on your Huawei mobile phone?

When I selected and tapped a .txt file in Files app on my phone, the text file would be opened with a stock editor app, WPS Office. It's fine. The default editor app for .txt file on my phone is WPS Office.

But when I tapped that floppy disk icon to save after editing, it seemed that it couldn't save and update that .txt file. It would rather 'Save as' another file.

I wonder why I could not save and update a .txt file directly. I look forward to something just like the Notepad on Windows PC.

Thank you in advance.