Did you try changing the category to something else, then changing it back to the category you want? We’ve got an issue with moving topics, and the behavior seems to be exactly the same,
I finally cut out the sample code that actually produced the three poll types and it posted ok.
I was copying and pasting the poll description information from here (the discourse cheat sheet)- and had put the first examples formated as “code” - and left the second three examples of “How they look” in the forum as they were. But then when that didn’t work, I cut out the “how they look” part - and it would post ok.