Well, yes, of course.
In Toolset > Post Forms > any_form you can duplicate forms.
Or you can just create a new one. I think, to test it, it would be better to create a new one, but I understand you want to clone maybe due to the form's complexity.
You could create a new one with just the basic needed settings.
I suspect, this is related to the same issue, and if we get this confirmed, we can try to find the BUG.
I can also help you do that on the staging site, please let me know.
I will do another test. I'll have a go next week and let you know. I'm not sure about the status as it was done on my old staging site - so maybe something else affected that. I'm going to copy my site over again and test on this updated staging site.
It does seem though that emails are failing to come through at all now (where I used to get two to one email account), but only when applying the particular settings you've numbered above #575043. I've tried a couple of times in my recent comments and indeed have not received anything.