Support cloning

I have been cloning multichoice-single-correct-answer questions for some quizes & updating + saving the new versions. The question is an image which the reader is supposed to identify. However, the questions revert back to the original correct answer with the new correct answer added and are seen as multichoice-multple-correct-answers. For example:

Question: What is Foo1?
Correct: Foo+1
Wrong: Foo-1
Wrong: Foo*1

Cloned (intended version after cloning, updating & saving):
Question: What is Foo-1?
Wrong: Foo+1
Correct: Foo-1
Wrong: Foo*1

But it becomes:
Question: What is Foo-1?
Correct: Foo+1
Correct: Foo-1
Wrong: Foo*1
...together which the remark from the site that the question appears to be multichoice-multple-correct-answers but is saved as multichoice-single-correct-answer.

The cloned question appears to be reverting even though I update the questions, update the correct answer & then saves. My workaround has been to 1) save the cloned question as multple-correct answers 2) untick the incorrect answer 3) save again 4) update as single-correct-answer 5) save again. But that is quite a lot of work. Am I missing somethin or is this a bug? Sorry if I have missed any similar postings, didn't find anything that matched this behaviour. Would be great if I could clone and get the updated cloned page correct after one save.