Need Some Help, UI API Called from background FIRAnalyticsQueue

Hi all, I am building two apps that run greatly in Android but for iOS. I have encountered a somewhat weird issue. When I am running ionic run ios, the app opens up perfectly. However, when i try to open it in the xcode project area. It produces runtime error. I’ve tried reinstalling the plugins and it wouldn’t work as well as checking any of my plugins I installed are causing this. But nothing works. The log is as below:

I am using:
xCode: 10.3,
Ionic: 4.12.0,
cordova: 9.0.0

Really appreciate any input in this particular issue, as I’m quite new to PWA as well.

Thanks in advance!