When I open the crafting materials panel and then move my cursor into the inventory on the right side, it closes the crafting materials panel.
I can safely reproduce this issue, the crafting material panel closes when the cursor crosses the border around the inventory slots.
If I open the crafting materials and then snap my cursor as fast as I can into the inventory, I can cross the inventory border without the crafting materials panel closing.
Sounds basically the same as this bug, but it doesn’t happen for me on equipped items/idols.