At the time, OnePlus confirmed that it had reached out to those who had experienced the issue and was looking into the bug. Two days later and OnePlus has officially confirmed in its forums that it is releasing a hot fix. OxygenOS 4.5.6 for the OnePlus 5 is an over-the-air (OTA) update that patches the 911 (or 999 in the UK) bug.
OnePlus does note in the forum post that this is a standard OTA update, which means it is an incremental release. Some folks may see the update sooner than others, but the rollout does begin today so it should land on devices soon. OnePlus says users should “upgrade to this build as quickly as possible.”
Have you received the update on your OnePlus 5 yet?