After brewing the potion of weakness in Realm and placing it in inventory, it showed visually that it had potion bottles in all three slots after exiting the interface after brewing one time and grabbing all potion bottles from slots. Since it still had that visual after checking if it had bottles, I broke the Brewing Stand with the bug visual showing and after it broke it didn't give the brewing stand back, I didn't take a picture of this because I didn't think of doing that. I will try it later to try and remake it. I have a Surface 1 Windows 10 Pro and it was in my Realm.

P.S. Its not 0.16.2 but in 0.16.1 but will try to see if its also in 0.16.2 soon.