Quark adds a mechanic that allows some tile entities to be pushed by pistons. Block placers and block breakers can be pushed using this mechanic by default. This is super useful, and normally it works flawlessly, but I found an edge case where this causes the inventory of the block placer to be deleted.

There's a specific configuration of blocks that causes this issue:

When the block is pushed so it's next to the redstone block, any items in the inventory disappear. Every other setup I've tested works fine. The block breaker also works fine when in the same configuration.

Versions:
Minecraft: 1.12
Forge: 14.23.2.2654
Open Blocks: 1.7.6
Open ModsLib: 0.11.5
Quark: r1.4-123
AutoRegLib: 1.3-16

latest.log file with the event occuring: https://pastebin.com/iRUaWju3

Testing was done in a clean environment with only the listed mods and JEI installed.