I use instruments to profile CPU workload IPC and L1Dcache miss rate.
I have 2 iphoneXR phone, A: ios12.2, B: ios 13.0
I use Xcode11.0, 11.2.1 try to catch CPU IPC value.
I can get correct value on A phone, but cannot get correct value one B phone.
B phone's value is very very big. and cycles and instruments get almost the same value.
I guess there is some bug on ios13, please fix it.
Can you try the new developer betas of iOS to see whether it reproduces for you?