First of all, ensure that both the NT1 5th Generation and audio software you are using are set to 32-bit float mode (note: some DAWs do not support 32-bit float recording – check out the User Guide for step-by-step walkthroughs).
Even in 32-bit float mode, you can still hear clipping while monitoring if the audio is too loud. Simply turn the mic input gain down and the clipping should disappear. Of course, in 32-bit float mode, you can still record this clipped audio and adjust after recording to remove the clipping.
If you are recording a very loud sound, it is possible you have exceeded the maximum SPL rating of the NT1 5th Generation. Like all microphones, the NT1 5th Generation has a maximum SPL (sound pressure level) which, when exceeded, can result in a small amount of distortion or clipping.
The NT1 5th Gen has a max SPL of 142dB, which is very high and will only be exceeded by recording an extremely loud sound source or recording very close to the capsule.