The reason for this situation is that the phone is entering recovery mode. Generally, when this happens, you can put the device into recovery mode to restart the device. For example: the computer cannot recognize the device, or it shows that the device is in recovery mode. The Apple logo appears on the screen for several minutes, but no progress bar appears. Or see the recovery mode screen.

Extended information:

iPad models with Face ID can press the Volume Up button and quickly release it. Press and release the volume down button quickly. Press and hold the top button until the device starts to reboot. Continuing to hold the top button will put the device into recovery mode.

On iPhone 8 or later, you can press the Volume Up button and quickly release it. Press and release the volume down button quickly. Finally, hold down the side button to see the recovery mode screen.

iPhone 7, iPhone 7 Plus, and iPod touch (7th generation) require pressing and holding the top (or side) button and the Volume Down button at the same time. Keep pressing both buttons to see the recovery mode screen.

Reference:

Apple-If You Can’t Update or Restore iPhone