We have tried soya milk (un/sweetened) and he wont touch either.
Koko and Alprosoya coconut - Won't touch.
Tried Oatly - Gave him the most horrendous watery loose nappies with just a small amount - Talking milk residue on a spoon followed by 6 watery nappies that day then 2 solid ones. Tried again the following day, much the same results.
Have bought some Almond milk... Wish me luck!