The bug
I gave a piglin a gold ingot, and while he was looking at it, I dropped another at his feet. The moment he finished with the first, he picked up the second and started walking while still looking at it.
How to reproduce
Isolate a piglin so no-one else picks up the gold
Give him a gold ingot
Throw another at his feet before he's finished with the first
Confirmed. This was supposed to be fixed, but it still happens when bartering via throwing a stack of gold.