Sonys Press conference from MWC took place end of February
If you missed it you can watch it here.
Please join the discussion here and share your thoughts on what was anounced here.
MWC 2019 discussion.
The return keys, man and the one on the right do not work anymore
I have translated your question to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Do I understand correctly that the back button and the recent applications buttons in the navigation bar are not working in your device? If that is the case, is the display damaged in any way?
If the display is not damaged, try and do the inbuilt test for the touch screen that you can find if you open up the Phone application > type in *#*#7378423#*#* > Service tests > Touch > Free drawing test.