Upvote:1
I can't answer for traditionalists who are not sedevacantists, but for sedevacantists there is no problem here. When there is a pope, we will follow him. I don't think your quotation from St. Ambrose was intended to imply that, during periods when there is no pope, the church and God disappear. (There have often been periods without a pope. Until recently, they were caused not by heresy but by the death or resignation of a pope.)