The situation with the Enter key was reported a few days ago and will likely be addressed in a future update. You might find some relief to the annoyance by trying Gboard from the Play Store in the meantime.
Can you please check the HDMI cable quality/connection, preferably switch the cable and try from there. That situation is unusual but consistent with a bad connection or quality of that cable. Should this be the case it can be causing the failings in the other components (sound) that you mention. I notice you refer to a U1 in the same spot. The HDMI cable gets in the U22-XJ in a 180º angle comparing to the U1 and that can cause some adverse tension if you are using the same cable that got eventually deformed in time to the position it used to have when connected to the previous box.
VPN issues are being taken care of as issues are already known.
Browsing with Chrome: please check my previous post in this thread, here above.