I'm not sure but this might be related to line breaks.
For instance, if you use FileZilla to transfer
exclude.txt from your PC to the Switch, and “Transfer type” is set to ‘Auto’ instead of ‘Binary,’ then line feeds are converted to line feeds plus carriage returns. This app seems to misbehave when line feed and carriage return are used instead of line feed only. Perhaps Homlet could tell us more, even though I'm pretty sure this wasn't intentional.
If you use Windows, then the default line break character is line feed plus carriage return. The usual way to fix this is install Notepad++, set line breaks to line feeds and open the file. Don't know if you can avoid installing an external program.
For more infos on how to use Notepad++, take a look at this:
https://github.com/Lord-Akkrand/Sky...Installing-Mods#configuring-your-plugins-file
You only need steps 3 (to open the file with Notepad++) and 4 (to set line breaks to line feed).