Hm, that's interesting. Just to make sure we're on the same page, you got the exact same error as before (with the text "Error in library(ALDEx2) : there is no package called ‘ALDEx2’")?
Not sure what the cause of getting that error again could be, but I looked it up and it seems like in the past this sort of error has been avoidable by installing ALDEx2's R dependencies through conda, rather than through R directly. Could you try running
conda install bioconductor-aldex2 -c defaults -c bioconda -c conda-forge
and see if this fixes things?
Sorry for all the trouble and thanks!
(I'm copying @dgiguer here in case he has any ALDEx2 wisdom 
)