When tethering and I answer a call, it stays on LTE?

I've noticed when i'm tethering using built in tether feature, and a call comes in, the phone still shows LTE and my speed on computer doesn't seem effected at all.

If i'm not tethering, it just shows 4G during a call.

Is the call going over LTE when tethering? I don't notice any more clarity than normal.