For a stack of 2 or more items in the advanced loot window - if a random roll starts, but is then stopped for that stack: - you cannot split that stack. - you may click the cog wheel to open a separate dialog box - the number field will contain the item count. It cannot be edited or back spaced over Server: Tunare This issue is observed while dealing with raid loot.
There's a slider above the number. Did you try moving that? I never type a number in ... always move the slider to the quantity I want to distribute. It's still working fine for me on Live.
This is expected behavior, you are not permitted to make any changes after the timer has started until it has completed. Let the timer run its course without having it roll and you can split it. Why does your ML have auto roll enabled for anything in raid chests tho?