Description of the Issue

This bug is similar to the following issue:
#3588

I have a text file in UTF-8 containing lots of text and the portuguese word "dá". When the file is closed and opened again, the program change the encoding of the file to TIS-640, buggin the word to "dรก-".

Just want to give this feedback, since uncheking "Autodetect character encoding" solves the problem.

Steps to Reproduce the Issue

1. Create a simple text file with UTF-8 encoding and the word "dá";
2. Save and close;
3. Reopen the file.

Expected Behavior

That the file would still have UTF-8 encoding and the word as was written.

Actual Behavior

The program changes the file encoding and bugs the word to "dรก-".

Debug Information

Notepad++ v7.8.5 (32-bit)
Build time : Mar 4 2020 - 11:04:20
Path : C:\Program Files\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS Name : Windows 7 Professional (32-bit)
OS Build : 7601.0
Plugins : mimeTools.dll NppConverter.dll NppExport.dll