Touchscreen not working properly on iPad and iPhone since update to IOS 17.6.1
Touch screen stops working. Can’t get back arrow or close ‘x’ to work.
I have to power off and back on and then it works for a while.
iPad Pro, iPadOS 17
See this article.
If the screen isn't working on your iPhone or iPad - Apple Support
Since the screen stopped working on both your devices, carefully consider what you may be doing to cause this. Perhaps, for example, you’re using a screen protector. Or perhaps you’re using some type of hand lotion.