I've started a new character in offline mode. I've upgraded all my gear to Simple (GS 20 items) but am stuck at GS 19 overall. I cannot fit an item into the BACK slot while there are 2 items Capelet & Pack) both wanting to go into the OUTERWEAR Slot. On my previous online characters the pack has gone into the BACK slot.
https://ibb.co/Wx6f4bX
I'm hoping that making the pack go into the BACK slot will fix my issue.
Further information: It turns out the the 2 affected items were reversed on the initial gear set, and making only 1 of the items caused the confusion as the new item wanted to go into a slot already filled and leave one slot empty. Making the second items corrected things as both items could now be fitte3d into their correct slots.