Help! Recording and mix issues

I’m having the same problem with parts of an audio recording missing - seems to just skip writing part of the take (3 and a half beats to be precise) somehow although there’s no obvious gap. I’ve just been trying my first real crack at recording so this is frustrating. I killed all the other apps on the iPad as originally I thought it might have been GuitarToolkit running in the background causing a problem. I’m using the Samson Go Mic with the USB Camera Connection Kit. Was trying to record a version of Money in 7/4 - don’t know if that might be significant in relation to the 3 and a half beats.