Pushing a chest with named map inside loses its name

Partner Rank: 4

Verification builds: Beta 1.12.0.4 release 2160393

Summary: Pushing/cloning a chest with named map inside loses its name

Impact: Unintended player experience and sad partner because a thing doesn't work the way it should.

Repro Steps

1. Download "The Traveling Trader" from the marketplace
2. enable cheats
3. teleport to 2012 87 70
4. put a button on the obsidian block
5. push the button
6. open the chest and mouse over the map in the chest

Observed Results: The map is incorrectly named "unknown map" once it's been pushed by the pistons. However if you were to open the chest before it being pushed you will see that the maps inside have the correct name "Savanna VIllage Map". In addition, if you split the stack, or move the stack of maps, the game seems to remember the names of the map and start displaying them.

Expected Results: The maps should still have the name "Savanna Village Map" whether the chest was pushed or not.

Screenshots/Videos attached:  https://youtu.be/TwUNCQq3Ro4

Regression builds:  didn't work in 1.11 either