Just a few days ago, we told you about an issue that was preventing some Apple iPhone XS and iPhone XS Max units from charging with the screen off. Some were able to get the battery inside their iPhone to charge up by awakening the screen, or by using wireless charging. And to make matters worse, some iPhone XS and iPhone XS Max devices showed the batteries charging even though, in reality, they were not.
The good news is that Apple plans on fixing this issue when it releases the final version of iOS 12.1 later this fall. Currently, there are developer and public beta previews of iOS 12.1 available, although we wouldn't recommend installing an unstable beta version of the operating system just to fix a charging problem. That's because there are a few workarounds that allow the units to charge. Beside turning on the screen, or using wireless charging, many have found that plugging out the Lightning cable and plugging it back in will allow their iPhone to charge.
As long as there is a way to replenish the depleted energy on your iPhone's battery, the best advice we can give you is to simply wait for Apple to rollout the final version of iOS 12.1. We wouldn't be surprised to see Apple push out the new build just before the October 26th release of the Apple iPhone XR.