When the phone has multiple backgrounds, the system load is relatively high and the CPU resources are seized, resulting in a lagging situation when the camera starts the preview. The preview lagging situation will disappear after the system memory is recovered and CPU resources are released.
After taking a photo, you need to wait about 3 seconds before tapping the thumbnail, because the background is still processing the photo after taking it. Tapping it immediately will cause the photo processing to be interrupted so an error prompt will appear.