hi @benjie_c and @therese' After extensive testing I can confirm that even preview does not work properly. There is 70% chance that if the tablet has been activated in the day at some point then Skype will call thorough but this is not guaranteed. If left for over 3 hours in standby, the tablet does not always wake when being called. It definitely does not wake if left overnight.
My folks are still using the older version of Skype on an old Samsung tablet and that is currently working.
I hope MS can sort this out because not everyone - like my folks who are in their 80's , dont speak or read english are unable to read any updates or cant tell if anyone has tried to call because they cant read the alerts that skype might leave. We've tried changing the language option but again, having not used technology before, they don't understand single word alerts - or they don't translate well such as 'accept' or 'next' or 'settings' .