I created an additional save so that the persistent file became changed as well, downloaded your file and gave it the name of the new created save file in order to match it with the persistent file.
I edited the Liz.rpy. I experimented even by removing the aunt condition completely and it also made no difference. No idea what's wrong there, but maybe the next version will fix it.
I believe you that it does work for you. But most probably there must be a bug so that under certain conditions, maybe if the player does not follow the expected path, this strange behaviour occurs.