I pay my credit card bill using Monzo. This requires me to add the account number (not card number) as the payment reference. This used to be sticky - every time I selected this payee, it would give me the same payment reference as the last time I paid them. Now, it puts the name of the payee as the payment reference by default, so I have to change it every time. I can’t think of any situation in which I would want to pay Jo Bloggs and have their payment reference be their own name - it isn’t helpful info for me or for them. Would it be possible to revert to the previous behaviour?
Mine shows what it was last time.
Have you tried uninstall, phone restart, reinstall?
I don’t think this is on a toggle or anything anywhere.
On iOS comes up below allowing you to select a reference you have used before
This hasn’t changed for me either. Where I’ve used multiple, tapping on the line reveals a pick-list of the previous for selection.
I had this problem however it is possible to set a default payment reference for saved payees which should fix this - hit ‘edit’ on the payee details screen 
Yeah the previous references totally broke for me (Android) when the payments tab got played with last year.
I’m on iOS.
Mine defaults to last used reference for that payee. I can tap on this to pick from a list of all previously used references for that payee or type a new one.
I’d actually prefer having a blank field by default (forcing active engagement with that field before transfer can be sent) but I do like that tapping on the field brings up list of previously used references.