I look at it like this, did yoho give an anti dote to alexis? sure we can safely say yes that is the case, does that mean that Alexis was indeed poisoned? no not really. You can recieve a heal when nothing is wrong with you. So now alexis won't get self since he won't die and we won't know if his theatre play is fake or not.
But if crowned is the poisoner here then tbh tbh I can see her poisoning alexis, but i find it odd he was not her first pick and she picked mango instead. But if memory serves me right she didn't really like either of them. So kinda checks out but would alexis poison someone last second? if the girl not gonna claim then this is all just mere speculations from my end.