Figured out what the issue was. At some point I added in 127.0.0.1 as a trusted proxy (don’t ask me why) and I didn’t realize this automatically turned off Home Assistant cloud (independent of using the iOS app).
When I tried to setup the iOS app again like I described it wasn’t able to connect to HA cloud for my instance because it wasn’t enabled. I wish there was a better error message to indicate the failure more clearly.