Merchant tabs locked

For some reason I'm blocked from adding new items to my merchant shop tabs. I can remove items, but even those once removed won't go back in. Not currency items btw, as I know those need to be sold via the currency exchange. I'm talking equipment, jewels, etc.

I've tried relogging which didn't seem to help. Is there a setting or something I'm missing? I can interact with my regular stash and guild stash just fine.

same problem here. Tried different things like restarting client, switching char etc.
I can take stuff out as well and cant put back in when i do. Happened after posting about 5 cluster jewels.