My experience is with IBM AT and OS 2 which had a Return and a numpad with an Enter. The AT and Model M keyboard at least were part of a very popular and influential generation or two of "PC".

https://en.wikipedia.org/wiki/Model_M_keyboard

EDIT: Holy cow, those Model M pictures are so nostalgic.

No, I definitely remember it behaving differently if I pressed "return" (right of "#" on the keyboard) vs "enter" (on the numpad).

EDIT: In the US I guess that's right of "'"? Below backspace, above the right shift.

The reason I remember is it took me quite a while to actually run the damn thing :P