iPhone 6S, OS 15.3. Screens freezes after updating OS. Keyboard also freezes at random. Tried restarting but no use.

Are you claiming that your iPhone 6S was not having these issues before you had updated to iOS 15.3?

What was the earlier iOS?

My iPad air three is suddenly freezing after being updated to iOS 15.3. I have taken the batteries out of my Apple keyboard which also seem to be having problems with the iPad. Seems to be internal to the iPad.

iPhone X bing similar issues. Screen scrolls to top of page on its own. Randomly selects items and freezes. Only occurred after iOS 15.3 update.