Never tried the multiplayer, but today I tried to create my MP party. But... I put my items on characters, exit and then re-clicked the "MP party" button and... Some items were back on Rudolph, and not on my characters. Why? Someone else had the same problem? I didn't sell item/played battle on single player after the exit ffrom MP party builder function.
There are separate saved "builds" for single-player and multiplayer. You must put on the items in the "MP Party" screen to save them for multiplayer. Is that what you're saying you did? If so, well, that's a bug.
Yes, I entered the MP Party builder and my Characters have some items on them. But if I try to put more items, after the exit and the re-enter on the page, the result is the same: the items are on Rudolph, not on my characters, so I think about a bug.