OnePlus
Enable or Disable SIM Card Lock auf OnePlus
The SIM PIN protects the SIM card itself, not your OnePlus lock screen. Enter it wrong three times and the network locks the card, asking for the PUK code from your carrier instead of the PIN.
This lock lives inside Android's security stack, separate from screen lock or fingerprint unlock. Disabling it stops OnePlus from asking for a PIN every time you restart the phone or move the SIM into another device.
Where to change it
Open Settings ➔ tap Security & lock screen ➔ tap SIM card lock. On a dual SIM device, choose the SIM slot you want to change first. Toggle Lock SIM card on or off, then enter your current SIM PIN and confirm with OK.
Turning the lock off removes PIN protection if the SIM gets stolen or moved to another phone; anyone can use it for calls or mobile data until your carrier blocks the number. Turning it back on asks for the PIN at every restart but has no effect on app lock, screen lock, or device-finding features.
If you already triggered three failed attempts and see a PUK prompt, this toggle will not help until the PUK code from your carrier unlocks the card again.