[SNAPSHOT #1519] Unknown variable or command '!=='

As pet title, since upgrading my dev box to the latest snapshot #1519 I’m seeing this error message in the logs when some rules execute.

The offending rule line is as follows

val door = fgDoors.members.filter[ item | item.lastUpdate("mapdb") !== null].sortBy[ lastUpdate("mapdb") ].last as ContactItem

If change the rule to use != instead then I get the same error.

Any ideas gratefully received!!

I would recommend that you file an issue on gitHub.
Include the log