Update does not move row across foreign partitions in v11

I've set up 2 instances of PostgreSQL 11. On instance A, I created a table with 2 local partitions and 2 partitions on instance B using foreign data wrappers, following https://pgdash.io/blog/postgres-11-sharding.html. Inserting rows into this table works as expected, with rows ending up in the appropriate partition. However, updating those rows only moves them across partitions in some of the situations: