I follow the sequence of restart: quickly press and release volume up, quickly press and release volume down, and then press and hold side switch, but no restart. What’s the problem?

Review the following just in case you are missing a step or not performing it correctly. Thanks.

(1) Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

(2)  If the above does not work then - Follow the instructions in this article by Apple ➔ If your iPhone is Non-Responsive or Frozen and see if that helps.

Axel F.