There's an appalling bug where, when using a crafting schematic you already know, you get both the message saying you already know it and you lose it from inventory. I got caught once unawares. and have unfortunately been caught twice more because, despite carefully scanning my list I've not spotted the one in question and accidentally thought I didn't have it. (I'm a schematic collector so my list is LONG.)
Yes, I've raised tickets. Fortunately none of the schematics in question were rare, although a couple were reasonably valuable (worth at least 8-10K on GTN.)
Yeah they fixed it long time ago but it is back again... I sent tickets for this one.