Poison Potion, Paralyzing Spider Venom stack attempt loses items

I just attempted (and succeeded) in crafting about 10 Paralyzing Spider Venom potions. Looked in the inventory and there was only one.

Figured it was a fluke and I carried that one and added it to my chest that already contained 1 Paralyzing Spider Venom potion and it looked (saw a brief flash reaction from the font in the chest list) that it was attempting to stack. but only one potion remained.

Closed chest, re-opened. Still only one.

So it appears that they are trying to stack -- but deleting every item past the first one.

 

Try logging out and then logging back in and check again?

 

have done so, several times. This isn't the first time it happened. The first time I wrote it off as a fluke. today I could reproduce it.