App Not working with a Wifi that is not owned privately

So ABSA knows that when you are using another companies Wifi to use their app that you wont be able to perform any payments on the app because most probably ABSA's firewall is clashing with that other company's firewall. It appears as if they have known about this for a while now because Ive seen a couple of complaints about this. My question is why don't they fix this?