XCode 64-bit emulation crashing

tl;dr: Why does my app not work on 64-bit emulations in XCode?

I’m running my Ionic app in XCode on all of the iPhone and iPad emulators. The app works as expected on all devices except for the 64-bit iPhone and iPad. For these devices I receive this error when I direct the user to the sign-in page for authentication (and the app crashes):

“error JSON.stringify()ing argument: TypeError: JSON.stringify cannot serialize cyclic structures.”

I am using simpleLogin for Firebase. Do you know why my app crashes on 64-bit emulators? Thank you.