Tumblr fixed the polls
client_ids are now generated by the backend (the frontend still also generates them, but those are ignored). This means no more multiple options activating when you select a single option and no more "wormhole" polls where voting in one also makes you vote in the other.
expire_after is limited to the range of 86400-604800, meaning polls can now last only a week, and you can no longer make polls that are shorter than 1 day. It is still possible to have any duration between a day and a week, but that's not as exciting as being able to make a poll last for 99999 days.
Slightly disappointing, but it was fun while it lasted and honestly, these were bugs that made sense to fix. So kudos to @staff for the prompt patching of the polls API.
Also, this is the blog I was using to test glitched polls before posting with my main; given that the polls are now fixed I won't be posting more.