m0useanswered grow question a year ago Plagues, no, not how plant pathogens work, they don't take chunks out of leaves. ....[][][]....
Fungus, again no, not how they operate in a plant, ....[][][]....
Heat stress, not lilkey, I could see heat stress being an issue and making the leaf more prone to damage when its younger but not common. ....[][][]....
This is most likely caused by some accident if its isolated, if there is more there could be a pest problem but there would be more signs and the bests would be visible. ....[][][].... Good Luck!