Happened to me as well, seems to be older villagers. Using Windows 10 home, AMD processor. Survival mode.
This has happened to me a couple of times now, Windows 10 64 bit, version 1.13-pre2. The second time it happened, two shulker boxes were placed at the same time. Neither one would open and both were destroyed by a silk touch pickaxe.
Spartan159
Happened to me as well, seems to be older villagers. Using Windows 10 home, AMD processor. Survival mode.