Our NFC normally works like a dream and is the best way to record your climbs. A couple of things to check:
You have a smartphone device with NFC. Unfortunately, some phones, including iPhones do not have NFC functions, or do not support NFC for non-financial applications. Check if your phone has NFC.
You have the NFC on your phone turned on. You can check this in your phone's settings.
The cover on your phone is blocking the NFC signal. Most are fine, but for some the cover can be problematic.
You will find the NFC signal from your phone is strongest at a certain spot in your device. This is normally the rear top third of the phone, but it depends on where the manufacturer has placed it internally. Once you find the sweet spot you'll be away!