14 month old Rhodesian Ridgeback, female. Slept through from first night home in a crate downstairs. Never any issues at bedtime. For last 3 nights wakes at 03.30 barking the house down. Taken to loo and does go then returned to carte where will bark and not settle rest of night. Doesn’t seem unwell. Prior to this barely barks, not even for doorbell. What could the cause be and how to resolve? I came down at 06.00, toileted and now asleep in playroom whilst I am sat on sofa. She is a nervous dog despite socialising but not horrendously so. Never been unhappy to be left in crate prior to this. Any advice gratefully received. Should we move crate? Should we leave door open?