If you hold fence(s) in your hand while attaching a lead to a fence, one of the fences in your hand is placed for a single frame, and then disappears. I found this while holding my last fence in my hand, and it was annoying. Then I found that by shift-clicking an item in your inventory, you get the fence back.
Environment
Minecraft Java Edition
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We're tracking this issue in MC-158774, so this ticket is being resolved and linked as a duplicate.
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