When a chest is stacked above another, the copper golem has a hard time recognizing it as a searchable chest. Resulting in multiple searching cycles before it recognizes the chest as valid. When a solid block is placed below a chest one block above the Copper golems current y-level, it does reliably search the chest. Only when two chests are stacked on each other (Like commonly done in regular gameplay) does the copper golem struggle to path find to the upper chest.
Expected result: The copper golem will search all available chests within reach before idling to repeating cycle.
Actual result: Copper golem struggles to search chests above its current y-level when placed upon another chest.
Video Link: https://youtu.be/gbRs682Qz6s
That_OneGuy
This behavior seems to be related to a check for blocks that can provide support in the 3x3x3 area around the chest. In the screenshot below, the golem easily finds the chest on top of a chest that has a grass block to the side and within 1 vertically. It takes a few cycles of searching to find the chest on a chest with no extra blocks around it.
[media]