I have an iphone X and even with IOS 14.1 I cannot succed to read a NFC tag. It does not work. Is there something I need to unable on settings?

Which NFC tag are you attempting on your iPhone X to read?

1) Try and Force Restart your iPhone exactly as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears then release the Side button (Can take up to 20 seconds. DO NOT release Side Button when invited to Slide Power OFF). 

(2) If that does not help your phone might need service ➔  Contact Apple for support and service - Apple Support

Axel F.