cannot breed horses and donkeys, and cannot put chests on donkeys even though i could previously

Ever since I got the horse update, i haven't been able to breed horses or donkeys at all. And I used to be able to put chests on donkeys but have recently been unable after my donkey with chests got stuck in a minecart and died 😞 I've also tried on survival to breed horses and donkeys and still hasn't worked.

(Sorry if this is bad its my first one XD the page saying how to make one wouldnt load on my lazy computer)