As far as I know there is no resolution to this if you want to use the real address fields. This is still a bug that happens. I am not sure 100% why but it probably has something to do with the way address fields are split up into multiple fields of their own.
There are several possible workarounds that may work for you. These are what I can think of but there may be more or better options.
1. Create your own text fields to act like the address fields, you can require these. You lose the ability to type an address and have it fill part of it in.
2. Change your process and find a way to utilize 2 forms. One form would have the normal address field on there but have it be required all the time. If a user is required to fill it out then send them to the required form only.
