As I play with my friend, I started noticing that my Runes of Shattering started disappearing. For two days, I’ve had that happen to me. In the third, which is the the day I’m typing this posting, I realized that I lost a Rune of Shattering a few minutes after my friend said he shattered an item. That triggered an alert in my mind and I told him. To test I asked him to shatter 2 items, consuming 2 runes. What happened was that after a few minutes, after having done a monolith with him, I lost 2 runes. So we have tested it again and I lost them again after a few minutes of him having used them. After that, what he did was that he would store items he wanted to shatter so that he could shatter them after I log off in order to not consume my runes. But when the gaming session ended and he told me he would shatter some items before logging off, I asked him to let me log off beforehand in order to make sure I don’t lose the runes. He went to shatter an item after I logged off and he noticed he didn’t lose any runes. I logged back in, and checked my inventory and, there it goes again, I lost a Rune of Shatter.
Summarization: My friend consumes my Runes of Shatter (I don’t know if this happens with other crafting materials) instead of his when shattering his items.
I don’t know how I could screenshot this in order to inform what is happening so I didn’t.
Note: I don’t know if its relevant, but I’m from Brazil and he is from Germany and we play on the EU servers. So I play with higher ping.