According to a user on Reddit that has been in contact with OnePlus, the 911 issue that came to light just a day or so ago has now been solved with an update. If unfamiliar with the problem, when OnePlus 5 owners tried to dial 911, it would cause the device to crash and reboot. This wasn't a something that affected all handsets but was confirmed to be a problem on more than just one. While annoying, this is quite serious and could have become life-threatening if left unfixed.
According to the user who has kept in contact with the firm and worked with them to produce a fix, log files from the OnePlus 5 were shared and the team at OnePlus was able to remedy the problem with an update. Unfortunately, the fix isn't a general one that can be shared and other users that are affected will have to wait a little bit longer until an official OTA update is released.