For 5 minutes I struggled with the door before I shouted for help - I was already late for work. Husband came upstairs and said, 'Lean against the door.'
'I've tried that!'
'No, do it again now.'
It seems that, as well as leaning against the door, we now have to lift it up at the same time, in order to unlock it.
I think I'll just prop my dressing-gown against it in future.
Still it wasn't as bad as the time I got stuck in the downstairs lavatory and had to call the gas man to let me out.