SMS writing jumps out the window in landscape mode

I recently bought the gs290 from the /e/shop. it is (essentially) nice but on writing SMS (with the default message app but I tried with other too, same issue).
When in landscape mode (ie with automatic screen rotation) I cannot finish any of my messages before the the cursor hops out of the window and goes outside the message(not clear where I end up maybe in a mode to attach elements).
Its difficult to say if it is peculiar keys combination but does not seem so. It is hard to reproduce but affects all my messages.
I tried to tweak the default Android Keyboard but cannot fix it. (this only happens in landscape mode). thanks for any idea/help.