Have you been unable to accept incoming phone calls on your iPhone X? You’re not alone, as a growing number of complaints on Apple’s support forums suggest the issue is not an isolated incident.

Some complaints date back to the beginning of December, with reports still cropping as of this writing. According to The Financial Times, Apple is currently investigating the issue.

While a number of iPhone X users have reported the problem, some owners of older iPhone models have also complained, including iPhone 6S and iPhone 8 owners, suggesting the problem is related to software, not hardware.

Apparently, when a phone call comes in, the display does not wake up, leaving users unable to accept or decline the call.

One user posting to Apple’s forums on Monday said the only way to briefly remedy the issue is to do a force reboot.

“I have a similar problem, sometimes the screen does not turn on and this problem can last for a few seconds or remains permanent until I do a forced reboot,” said luca297. “I have already sent my phone to service but have not encountered any problems with [hardware].”

Apple’s iOS 11 has been plagued by problems since it launched in September, forcing the company to address several issues, including one that was found to render iPhone models useless. Apple’s software problems have become so prevalent that the company is putting a priority on ensuring iOS 12 is devoid of issues when it launches, rather than introducing big new features.

It’s ironic that a phone can’t perform a basic function of what a phone is designed to do. With iOS 11.3 currently being tested in beta, hopefully users can expect a fix soon.