Quite often when block is placed where dropped items are the items stay "inside" the block. Every time this occured the items had only one or two ways to escape (like sides where wasn't placed block)
Most often this happened when the items had only way top "exit" way
Thank you for your report!
However, this issue is Incomplete.
Your report does not contain enough information. As such, we're unable to understand or reproduce the problem.
Please review the guidelines linked below before making further reports.
In case of a game crash, be sure to attach the crashlog from
[minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/guides/finding-minecraft-data-folder].Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki