Significant lag on a newly installed /e/OS 2.8 (updated 2.9) on Fairphone 5 until Camera app is opened

• /e/OS version: 2.8, 2.9
• Device model(s): Fairphone 4, Fairphone 5
• Impacted Application: /e/OS

The problem

Significant lag and slow response can be observed on a newly installed /e/OS 2.8 (updated to 2.9) on Fairphone 5 until the user opens the Camera app. After the user opens the Camera, the issue stop to occur until the screen is locked or the device is rebooted.

/e/OS Foundation Community thread, dedicated to the issue: https://community.e.foundation/t/fairphone-5-lags-if-camera-not-opened-first/67615

Steps to reproduce

1. Install /e/OS 2.8 on Fairphone 5;
2. Turn on "Smooth Display" setting in Settings -> Display;
3. Lock the device;
4. Unlock the device;
5. Observe the delay in response to actions;
6. Open Camera app;
7. Close Camera app;
8. Observe the significant improvement in responsiveness of the system.