EDIT 2020-01-07 03:55 GMT: OnePlus started rolling out the 184.108.40.206.KB05BA hotfix, which has already been added in the app. It seems this build fixes all lag issues.
EDIT 2020-12-30: we mistakenly wrote that this update came with the December patch. It has the November patch instead, and the article has been edited to remove the incorrect information.
It's already bad enough that we're getting a November patch at the end of December, but this update also has yet another lag issue. Some of you have already emailed us about this, but for those of you who haven't yet installed this update, here's a list of possible workarounds to fix the issue:
- Enable battery saver mode
Settings -> Battery -> Battery Saver
Staying on battery saver mode seems to be a workaround, as reported by multiple people on OnePlus Forums. Note that you will have to stay on battery saver, as the issue goes away only while on battery saver mode.
- Disable Google Assistant Voice Match
Settings -> Google -> Account services -> Search, Assistant, and Voice -> Google Assistant -> Voice Match
This solution has been reported by users on forums as well, though we're not sure why this fixes the problem.
- Record a short video from your camera and play that video back in your gallery
This sounds the most absurd, but it somehow fixes all lag issues. You can delete the video afterwards. Thanks to @coldfire on our Discord server for suggesting this. It would work even for a audio record from the built-in recorder app.
You can try either of the listed workarounds, though I'd highly recommend the last one. I've personally tried it, and it works. It also doesn't come with any compromises, as is the case with the other two. If any solution works for you, or if you have a new/unlisted solution, please do email us or send a message on our Discord server, so that other users are made aware of it as well.