Also, some banks are asking for a Yellow Book in order to open a bank account. Might not be essential but the more arrows you've got in your quiver, the better. Get your appointment booked at the embassy as I had a two week wait for a vacancy.
K-Bank were willing to open with Non-O visa supported by wife with house book and marriage certificate etc. SCB were asking for me to produce a Yellow Book in addition.
Maybe better to do on a computer rather than on a phone? Or at least it gives you another option. This will be a software glitch and I experienced the same at one point, in not being able to enter the information requested. I was eventually able to enter it though, one way or another. There could also be variations between iPhone and Android apps, depending on how well debugged the software for each platform is!
Ignore the request and expect refusal. Surely you can speak to someone to voice your concerns, with a view to amending the requirements, but at the end of the day, if you want to risk refusal and loss of the application fee, ignore the request at your peril. Contact your ex first to see if there will be any objections on her part to supplying the information requested. Pride comes before a fall.