tough one today, this is I'm pretty sure the literal only word in english that satisfies these requirements
Ah yeah, that day was tricky. I think the second-to-last rule may have tripped you up a bit. Maybe you tested something like a, ae, aei, aeio, aieou?
It’s really cool that you were able to get one that fit all of these rules, though!
Here’s some other words that would have worked for that day, but I’ve used ROT13 on them to avoid spoiling anybody:
vapyhqr
vyyhfgengr
vzcrghf
vzcebzcgh
vaabphbhf
I generally made sure the code finds a set of words that includes several possible answers so that it avoids there ever being “only one possible word in English that fits”