Camera/Sensor with MIPI interface should output HS/LP signals using the same lane.
Are you using UltraScale+ devices ? -- If this is the case, you should HP IO pin with VCCO=1.2V
Or are you using 7-series devices ? -- If yes, please follow suggestion from XAPP894. You need to implement a resistor network or using 3rd vendor PHY device. This doc suggest using LVDS 2.5V for HS signals.