User Defined Language in Notepad++ ignores first line when comment position is set to “Force at beginning of line”

I am trying to create a User Defined Language for Notepad++ where ! at the start of a line denotes a comment. However, if I set the “line comment position” to “Force at beginning of the line”, any comments on the first line of a text file get ignored.

If I set the line comment position to “Allow everywhere” or “Allow preceding whitespace”, the first line is marked as a comment as expected. However, there is no preceding whitespace on the first line, so that shouldn’t be necessary.

How do I prevent Notepad++ from ignoring comments on the first line when using my User Defined Language, while also requiring the comment marker be at the start of a line?

Notepad++ not highlighting first commented line