The wrong app opens when I use an NFC reader
The wrong app might open because it is set as the default app to use with an NFC reader.
You might need to remove or reset the default app for the NFC reader. Tap Settings > App Manager > Default Apps to
remove the app as the default app for the NFC reader. The next time you tap your device against the NFC reader, set the
preferred app as the default app.
NFC is not working as expected
If you try to share a file by using an NFC connection or a smart tag when your device is locked and the backlight is off, or
when the power is turned off, NFC will not work. Settings in the Allow NFC Card Transactions section of the NFC screen
don't apply to NFC file transfers or the smart tag feature.
You can set up your device to run some NFC apps when your device is locked and the backlight is turned off, or when the
power is turned off. In the NFC settings, the When locked or backlight is off option applies to NFC apps that simulate
physical card transactions, (for example, credit card payments or security badges that allow access to secure buildings),
and NFC transactions handled by your SIM card. The When device is turned off option applies only to NFC transactions
that are handled by your SIM card.