UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: channel closed
Seems there is a unhandled promise rejection that maybe should be handled… (just guessing from the error message)
Did you remote debug the problem on the device already? Follow these instructions here to debug the problem in Safari dev tools: https://ionic.zone/debug/remote-debug-your-app#ios Look at the console and network tabs for errors.
What is your ionic info output?