Messages bug in the scenario editor?

Anyone else encounter a problem in the scenario editor where the majority of the typed out history page in the messages gets erased when you edit a different part of the page? For example the scenario instructions, hints stay the same but if I edit the history part a small bit then 2 paragraphs get erased clean. Has anyone else come across this issue?

What game is this issue occurring in?

Age of Empires 1 Definitive Edition