Audio scaling problem

[Koalllla]

I use a Raspberry Pi and a HiFiBerry DAC + ADC pro to do some test on audio. There is no Auto Gain Control on the HiFiberry so this shouldn't be the problem. I need to simultaneously play a sine wave and record it at the input via a loopback. I am able to record the signal but the signal is significantly higher than what I send in. When i send a sine wave with max value of 1 I get a max of 1.395 and when plotted it seems the entire signal is higher than what I send out. I do need an exact copy of what I get at the input because I need to do gain calculation and manually scaling isn't something I can do. I will attach the code if someone wants to look at it. Has anyone else ran into this?
test.txt