I don’t speak Mac, but that behaviour looks like you’re trying to use 32-bit plugins on 64-bit version of Audacity, which won’t work. You need the 32-bit version of Audacity for that.
BTW the free version of Grallion2 does autotune, & has a 64-bit Mac version.
https://www.auburnsounds.com/products/Graillon.html
[& 32 bit mac … Auburn Sounds - Where may I find older versions? ]