That is probably one of the problems with shidduch dating. If two people meet on their own and like each other they usually don’t find these things out until they have already become friends and realize they want more than a friendship. By that time they know the whole person and don’t look at them as a disease. It just comes along with the territory.
On the other hand, with shidduch dating, you turn over every stone to get the scoop on the prospect and their family so if one toe is longer than the other you will know about it and nix the shidduch.
We are illogical when it comes to these things. Hashem can give us these nisyonos at any time. He can give it to anyone even to a perfect couple with no signs of illness before a wedding and poof someone gets sick after a wedding and has to deal with the same thing. We are truly blinded by perfection and do not have enough bitachon and emunah to know and understand that Hashem has our zivig picked out for us and some may come with bumps and bruises, not everyone is a perfect peach.