iPad display issues after iPadOS 26 update

Since updating my iPad to iOS 26 the display behaves erratically.

1) Open windows at random moments will switch from full screen to a smaller window governed by the ‘traffic light’ controls zzzzzzzzzz then instantly switches back to full screen.

2) App windows open spontaneously of their own volition and then behave as in 1)

zzza zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Aaazzazzzzzzzzzzzzzzzzzzzzzz zzzz zzzz

I started to type any ideas and all the zeds appeared with no pressing of z or the selection of underline.

[Re-Titled by Moderator]

Original Title: ilusK 26 typoowowpqoteqwwttioyoto