Notepad++ 8.5.5 removes/hides control characters when switching to a different tab

[przemo20]

Description of the Issue

After updating Notepad++ 8.5.4 to version 8.5.5, when you open some, e.g., EXE/XLSX file the control characters are displayed correctly, but when you switch to a different tab or open a new one (Ctrl + N) and then go back to the tab with the previously opened file, the control characters disappear.

Steps to Reproduce the Issue

1. Clean install Notepad++ 8.5.4
2. Launch it, then go to View → Show Symbol and uncheck the “Show Control Characters & Unicode EOL” option and close the program
3. Install N++ 8.5.5 (without uninstalling the previous version)
4. Launch it, open some EXE file with Notepad++ (for example, let's open the N++ installer for version 8.5.5) – you should see the control characters correctly
5. Switch to a tab with the “change.log” file open, then go back to the “npp.8.5.5.Installer.x64.exe” tab – control characters are gone

If you want, you can now open another file; control characters will be visible again, but when you switch and go back, they're gone again.

Also, you can skip the first three steps by just editing the config.xml file (%AppData%\Notepad++) – changing the value of ccShow to no.

Expected Behavior

Not entirely sure. Probably, if we have “Show Control Characters & Unicode EOL” disabled, it should stick to it and not show the control characters at all.

Actual Behavior

Check the “Steps to Reproduce the Issue” section.

Debug Information

Notepad++ v8.5.5   (64-bit)
Build time : Aug  7 2023 - 18:44:22
Path : C:\Program Files\Notepad++\notepad++.exe
Command Line : 
Admin mode : OFF
Local Conf mode : OFF
Cloud Config : OFF
OS Name : Windows 10 Pro (64-bit)
OS Version : 22H2
OS Build : 19045.3208
Current ANSI codepage : 1252
Plugins : 
    mimeTools (2.9)
    NppConverter (4.5)
    NppExport (0.4)

After opening the file:

After switching to a different tab and going back to the tab with opened file:

[alankilborn]

Simplified STR (Steps to Reproduce), but trying to keep the "spirit" of the OP's STR:

• extract a fresh portable 8.6.4 (current vers. as of this writing) and run it
• uncheckmark the View > Show Symbol > Show Control Characters & Unicode EOL menu option
• open change.log into a tab via drag and drop from Explorer
• open notepad++.exe into a tab via drag and drop from Explorer (observe: much inverse video as control characters are [wrongly] being shown)
• activate the tab for change.log
• activate the tab for notepad++.exe (observe: no more inverse video characters as control characters are [now correctly] not being shown)