Please consider this issue that has been created more than one year ago: https://sourceforge.net/p/notepad-plus/bugs/4095/
“ANSI as UTF-8” is an incorrect, misleading and confusing term, which does not exist outside Notepad++.
In addition, it is inconsistent with the rest of the UI. Please replace it with the correct term “UTF-8 without BOM”.
Please do not ignore this issue. It’s very easy to fix.