Forgot to save the replay, but in a PU room tour game, my Pyukumuku was Taunted by Sableye and I was holding the Poisonium Z item. I was going to use Z-Toxic to poison the Sableye anyways but for some reason Z-Toxic was a Normal move.
When I clicked on the move, this happened
Not only this, but it made it seem like I had already made my selection and I was waiting on my opponent, if I wasn't looking, I could have timed out despite clicking my move already. Needless to say, I had to switch out, but yeah Z-Toxic is apparently broken when I had to struggle. I don't know how far this glitch extends, but it does at least for Z-Toxic. Checked this again with esteemed user TJ afterwards and same thing occured.
Then UberSkitty suggested we try Normalium Z. I was like okay, same thing is gonna happen except Struggle will turn into Z-Block I can't click. Wrong. This happened...
We tried it with Soak and the same thing happened with Z-Soak as Z-Block. So we tried moveslots and same thing happened as Z-Toxic when Toxic was first moveslot, so its moveslot dependent.
I asked the Help room what the mechanic was and they said that when you are taunted into struggle you can't use any of your z moves. If this is true, then there really shouldn't be a Z-Move option (or at least it shouldn't allow you to click Z-Struggle). If this is false, I can't click my Z-Status move, and when my Z-Status move isn't in my first slot it's wonky.
Thanks to
Specs Jigglypuff TJ and
UberSkitty for helping