Why does a RYOBI 18V ONE+ HP Brushless 30-34° Framing Nailer turn off by itself?

Auto Shut-Off & Reactivation – RYOBI 18V ONE+ HP Brushless 30–34° Framing Nailer

As a safety feature, the tool automatically powers down after a period of inactivity.

You’ll need to reactivate the tool under the following conditions:

• After replacing the battery
• After 20 minutes of inactivity
   

To reactivate:

1. Squeeze the grip switch located beneath the main trigger.
2. The LED will glow green for 10 seconds, indicating the tool is ready to use.