Apple’s latest iPhone is off to a better start than the Google Pixel 2 XL, but the iPhone X isn’t completely free of issues. Owners of the iPhone X have shared their units are being affected by a green line on the display and unresponsiveness in cold weather. Both issues have been brought to Apple’s attention, and now there’s another hardware-related problem on the rise.

Another wave of iPhone X owners have said one of the device’s speakers are producing crackling when the volume level is raised.

It’s the top stereo speaker on the iPhone X that’s being a hassle. Reports found on Twitter, Reddit, and the comment sections on various websites reveal the earpiece-based speaker is making noises of its own. If you put the iPhone X’s volume at a high level or use speakerphone, you’ll notice the top speaker begin to crackle.

Don’t expect to get a replacement and have things fixed, though. Apple has swapped affected units, but customers are saying the replacement units still have the issue.

The iPhone 8, which was released in September, faced a similar problem. However, Apple’s secondary flagship was producing the crackling at any sound level. Here the iPhone X seems to be crackling when the sound level is high. Apple was able to fix the iPhone 8 with a software update, so the same is likely for the iPhone X.

As it continues investigating, Apple is collecting information from affected units to figure out the root of the issue.