This is probably the device's lockout feature.When this feature is on: If you try 10 invalid times (like wrong cards or bad fingerprints), the device locks for 10 minutes. Nothing will work during this time. It'll go back to normal on its own after 10 minutes.

This usually happens because the keypad reader's password output format isn't set correctly.For our C1/2/4 controllers: Set the reader's password output format to 10-bit virtual card number (this matches our controllers).
For other brands' controllers: Set the reader's password output format to one of these: 4-bit, 8-bit, or 10-bit virtual card number (match the controller's supported format).

That's the LDR (light-dependent resistor) anti-tamper alarm—it triggers a default 1-minute beep when bright light enters the device through the LDR component.
Fixes: Enter programming mode and disable the alarm with the 50# command or Cover the LDR component with black tape (blocks light to stop beeping).