I am onto the traitor part of this quest, i save one advisor and take the prince and said advisor downstairs to the cellar.
Then obviously I have to go get the other one but the upstairs door to get thru to the area where the advisor is just will not open to the (A) button press.

I have tried exiting the area but I also cannot because the zone is locked until this quest objective is complete.

So I am locked out and cannot progress any further - I am effectively stuck!

I have tried to save and reload; or save and reload app - door still will not open.

or try another save and go thru the whole cutscene and event again, and again when I get to this door, even with the prince in tow it is still stuck/will not respond to open prompting!

Help!