Come back after 3 years

If this is the only damage "isolated" on the leaf its likely just from wear and tear. If there is other damages on other leaves that looks the same more likely a pest. To me this does not look like pests given how the damage looks, might have been pinched when the leaf was forming or something. Good Luck!

löcher machen raupen/schnecken usw, sollte also leicht zu erkennen sein.