Distortion n headphones only

Using Cubase AI along with a Steinberg UR22MkII on Win 10. Why would I get distortion in my headphones when recording a vocal but NOT when playing back the recorded vocal? Thanks in advance for any comments.

What headphones do you use? HPs with higher impedance usually need more power(volume) to hear it loud. My Sony is 68ohm and my AKG is 600ohm. They need hugely different volumes to hear the same loudness level coming out of the headphones out of my DA converter.

It’s not a matter of volume. My AKG K240’s are 4-600 ohms (marked on the right earpiece). Always had plenty of volume. The K240’s are probably beginning to show their age since I’ve had them for 30 years or so. Beginning to have intermittent distortion. Could be cable, connector, driver. Time to dig in or get a new pair.