notes.app – MacOS misbehavior with Fonts in the Notes app

I can’t figure out if I’m in a certain mode or if there’s a bug in the app but whenever I try to increase or decrease the font of text in the Notes app the direction is always to go Bigger

Format -> Font -> Bigger
Format -> Font -> Smaller

Is there any explanation for that? Is the Notes app buggy when pasting in formatted text from webpages and html in general? I can’t make heads or tails of this behavior.

Notes -> Format -> Font