iOS build working fine in debugging but not in distribution/testflight

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SOAP

iOS

Xcode

The ios build is working fine while debugging and the build is not working when generating an .ipa or downloading build from TestFlight (Appstore > Prerelease)

I have rechecked the build provisioning profiles, They are perfectly fine.

I am able to download the app from testflight too, but the screens are stuck at some point (when there is an API call). The app is using SOAP services and the app got transferred from another itunes connect.

The same services are working fine when device is in debugging mode.

Thanks in advance.