Network map stopped updating on testnet staging notary

The testnet staging notary has stopped updating its network map. It appears to be stuck in retrieving the bytes from the network map and isn't timing out.

The symptoms of this are that new nodes on the network cannot notarise transactions. The node's database does not contain any of the new entries.

Attached is a folder containing the jstack and entire log history since upgrading to Corda Enterprise 3.2.20190215

Note that the jstack was repeated several times in succession over a period of several minutes and each time showed the exact same stack trace on the network map updater thread.