Late Tuesday night, AT&T customers experienced a significant network disruption that left many unable to connect to their wireless service. The issue, which led to some users seeing “SOS” instead of their usual signal bars, has since been resolved.

According to AT&T spokesperson Jim Kimberly, the company has addressed a software glitch that affected a limited number of users. In a statement, Kimberly apologized for the inconvenience and thanked customers for their patience while the problem was fixed. The disruption began around 4 PM ET and continued until late at night, as tracked by Downdetector.

During the outage, affected customers took to social media to report issues, including being stuck in SOS mode or losing service altogether. Contrary to an earlier report from The Mobile Report suggesting that a failure at a switching center was to blame, AT&T clarified that this explanation was inaccurate. The company also noted that some users on Reddit had reported problems with Android devices, not just iPhones.

This incident comes shortly after AT&T reached a settlement with the FCC over a previous 911 outage and amid ongoing negotiations with the Communications Workers of America in the Southeast. The outage was resolved by early Wednesday, and AT&T has reassured its customers that service should be back to normal.

For now, AT&T customers should find their connectivity restored and are encouraged to reach out to the company if they continue to experience any issues.