A week after the third beta of iOS 11.4 was released, a fourth new beta of the next update to Apple’s mobile platform has been released to testers. For those who have a device registered in the Apple Beta Program, you should see the update as available to download to your compatible device.
The beta released today is a bit of a surprise given Apple usually spaces out their updates several weeks during beta testing. The quick release likely indicates that an issue was discovered and needed to be patched quickly but Apple has not confirmed this fact.
So far there is nothing new to report on this latest beta to iOS 11.4. It is still focused on Messages in iCloud and AirPlay 2, both of which have been in the beta cycle for a while now on this build. As posted on earlier, it looks like HomePod will be picking up Calendar support in this update too.
If you are interested in joining the Apple Beta program, you can do so at this link. Remember that the hint is in the name. It is beta software that you will be running so you could (likely) run into bugs during the testing process.